ASME Conference Presenter Attendance Policy and Archival Proceedings

2014;():V004T00A001. doi:10.1115/DETC2014-NS4.

This online compilation of papers from the ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference (IDETC/CIE2014) represents the archival version of the Conference Proceedings. According to ASME’s conference presenter attendance policy, if a paper is not presented at the Conference, the paper will not be published in the official archival Proceedings, which are registered with the Library of Congress and are submitted for abstracting and indexing. The paper also will not be published in The ASME Digital Collection and may not be cited as a published paper.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design for Additive Manufacturing

2014;():V004T06A001. doi:10.1115/DETC2014-34072.

This paper introduces a novel design optimization method to optimize models with multiple material layers and complex cross-sections, for desired behavior. The developed optimization procedure utilizes an upscaling approach to approximate a full scale finite element (FE) model, by only analyzing a small material volume element. This approach requires less modeling efforts and is computationally less expensive than the full scale model. The developed method helps in building computationally efficient models for obtaining desired deformation behavior. The efficacy of the proposed method is illustrated through a couple of example design problems.

Commentary by Dr. Valentin Fuster
2014;():V004T06A002. doi:10.1115/DETC2014-34408.

Tissue engineering (TE) integrates methods of cells, engineering and materials to improve or replace biological functions of native tissues or organs. 3D printing technologies have been used in TE to produce different kinds of tissues. Human tissues have intricate structures with the distribution of a variety of cells. For this reason, existing methods in the construction of artificial tissues use universal 3D printing equipment or some simple devices, which is hard to meet requirements of the tissue structure in accuracy and diversity. Especially for soft tissue organs, a professional bio-3D printer is required for theoretical research and preliminary trial. Based on review of the exiting 3D printing technologies used in TE, special requirements of fabricating soft tissues are identified in this research. The need of a proposed bio-3D printer for producing artificial soft tissues is discussed. The bio-3D printer suggested consists of a pneumatic dispenser, a temperature controller and a multi-nozzle changing system.

Commentary by Dr. Valentin Fuster
2014;():V004T06A003. doi:10.1115/DETC2014-34658.

Various energy sources are available for sintering and/or depositing the material in additive manufacturing for metallic objects. These can be mainly categorized as laser based, electron beam based and arc based. While laser and electron offer better surface finish, it is possible to achieve high deposition rates in arc based weld-deposition. The inferior surface finish can be compensated by going for a hybrid system, combining deposition and machining. Twin-wire based weld-deposition, used in the present work, makes it possible to even realize functionally gradient material matrix; the use of two different filler materials into a single weld-pool makes this possible. Wire speed, torch speed and filler material are important factors that effect the composition of the deposited volume. Determination of the operating range and effect of these process parameters therefore is important to control the properties of the weld-deposited gradient objects. The current work presents the material composition of two filler materials ER70S6 and ER110SG with different wire speed and torch speed. Deposited material elemental compositions were analyzed using ED-XRF machine.

Commentary by Dr. Valentin Fuster
2014;():V004T06A004. doi:10.1115/DETC2014-35060.

Current additive manufacturing processes mostly accustomed with mono-material process plan algorithm to build object layer by layer. However, building a multi-material or heterogeneous object with an additive manufacturing system is fairly new but emerging concept. Unlike mono-material object, heterogeneous object contains multiple features or inhomogeneous architecture and can be decomposed into two dimensional heterogeneous layers with islands where each island represents associated feature’s properties. The material deposition path-plan in such multi-feature/multi-contour layers requires more resources and may affect the part integrity, quality, and build time. A novel framework is presented in this paper to determine the optimum build direction for heterogeneous object by differentiating the slice based on the resources requirement. Slices are bundled based on the heterogeneity and the effect of build directions are quantified considering the feature characteristics and manufacturing attributes. The proposed methodology is illustrated by examples with 50% or more homogeneous slices along the optimum build direction. The outcome would certainly benefit the process plan for multi-material additive manufacturing techniques.

Commentary by Dr. Valentin Fuster
2014;():V004T06A005. doi:10.1115/DETC2014-35408.

The layer-by-layer nature of additive manufacturing (AM) allows for access to the entire build volume of an artifact during manufacture, including its internal structure. Internal voids are accessible during the build process and allow for components to be embedded and sealed with subsequently printed layers. When AM is combined with Direct Write (DW) of conductive materials, the resulting hybrid process enables the direct manufacture of parts with embedded electronics, including interconnects and sensors. However, the hybridization of DW and AM technologies is non-trivial due to (i) identifying DW materials and processes that are compatible with AM infrastructure, throughput and resolution, (ii) temperature processing requirements, and (iii) interactions between the two materials.

In this paper, the authors explore DW technologies and materials to identify those that are most compatible with AM. From this exploration, the authors abstract a set of generalized design considerations for the design of a hybrid AM and DW process. These considerations are then employed in a systematic design process in which a DW system for depositing conductive materials during the PolyJet manufacturing process is realized. The resulting system is able to create embedded functional electronic interconnects and sensors in printed parts composed of both stiff and flexible polymers.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design for End of Life Recovery

2014;():V004T06A006. doi:10.1115/DETC2014-34309.

Remanufacturing is becoming an important business as market demand for remanufactured products increases and environmental legislation puts further enforcement on Original Equipment Manufacturers (OEMs). However, profitability of salvaging operations is still a challenge in remanufacturing industry. Several factors influence the cost effectiveness of remanufacturing operations, including variability in the quality of received used items and uncertainty in the quantity of return flows and the market demand for those products. Remanufacturing companies need to handle these sources of uncertainties in order to improve their profitability. The current paper develops a Stochastic Optimization method to model these sources of uncertainties in take-back and inventory planning systems. The main purpose of the model is to determine the best upgrade level for a received product with certain quality level with the aim of profit maximization. An example of personal computer is provided to show the application of the method.

Topics: Uncertainty
Commentary by Dr. Valentin Fuster
2014;():V004T06A007. doi:10.1115/DETC2014-34757.

In the United States alone, millions of tons of waste are generated every year, highlighting the urgency for innovative solutions for waste management. Traditional strategies of reducing the amount of End-of-Life (EOL) products include reuse, recycle, remanufacture and disposal. Recently, resynthesis has been proposed in the design community as an alternate approach that aims to combine assemblies/subassemblies of EOL products from multiple domains to create a ‘new’ product, distinct from its parent products. The original work on resynthesis assumes that there is an equal demand for ‘resynthesized products’ based on the available supply of EOL components that the resynthesized products are composed of. Furthermore, the price was assumed to be equal to the price of similar products on the market. However, such an assumption may underestimate or overestimate the value of resynthesized products, which in turn impacts the demand of these products. Recent research has shown that customer reviews express customers’ true opinion and value for specific products or product features. The authors of this paper propose a data mining methodology to quantify the price and demand for resynthesized products by mining user-generated reviews of products publicly available on the internet. A case study involving a resynthesized electronic mouse and white board eraser is presented to demonstrate the feasibility of the proposed methodology.

Commentary by Dr. Valentin Fuster
2014;():V004T06A008. doi:10.1115/DETC2014-34779.

The United States generates more than 250 million tons of municipal solid waste (trash/garbage), with only 34% being recycled. In the broader global environment, the problem of waste management is becoming increasingly relevant, demanding innovative solutions. Traditional End-of-Life (EOL) approaches to managing waste include recycle, reuse, remanufacture and disposal. Recently, resynthesis was proposed as an alternative to traditional EOL options that combines multiple products to create a new product distinct from its parent assemblies. Resynthesis employs data mining and natural language processing algorithms to quantify assembly/subassembly combinations suitable for new product combinations. However, existing resynthesis methodologies proposed in the design community have been limited to exploring subassembly combinations, failing to explore potential combinations on a materials level. The authors of this paper propose a material resynthesis methodology that combines the materials of multiple EOL products using conventional manufacturing processes that generate candidate resynthesized materials that satisfy the needs of existing domains/applications. Appropriate applications for a resynthesized material are discovered by comparing the properties of the new material to the functional requirements of application classes which are found using clustering and latent semantic analysis. In the course of this paper, the authors present a case study that demonstrates the feasibility of the proposed material resynthesis methodology in the construction materials domain.

Commentary by Dr. Valentin Fuster
2014;():V004T06A009. doi:10.1115/DETC2014-34955.

Historically, products have been developed following the “we design it, you build it” approach. Design and production belonged to two independent entities, with no feedback from downstream activities to upstream activities. In order to avoid redesign costs caused by the lack of feedback, pioneer organisations began to apply methodologies such as ‘Design for Assembly’ or ‘Design for Manufacture’ on a daily basis.

Over the years, further research has been carried out to refine these generic methodologies adding previously unconsidered perspectives, such as quality, reliability, environmental, etc. which evolved into a concept called ‘Design-for-X’ (DfX). However, existing methodologies have largely focused on simply reducing product’s structural costs, without taking into consideration other important aspects of more complex assembly processes common in the aerospace industry.

The complex assembly process that this paper focuses on is the systems’ installation process within the aerospace business. The installation of fuel, electrical and other systems must follow strict aerospace regulations, intra-organisational design rules, safety policies and many more restrictions, which are not considered as key factors in current methodologies.

In this paper, we endeavour to provide an extensive analysis of existing DfX methodologies and support our conclusion that there is an opportunity to develop a new methodology which will ease the aerospace systems’ installation process for the shop-floor operator.

Topics: Manufacturing , Design
Commentary by Dr. Valentin Fuster
2014;():V004T06A010. doi:10.1115/DETC2014-35524.

Ti-6Al-4V is a popular aerospace alloy employed in various aerospace structures and their critical components. Irrespective of cause, a defect of few cubic millimeters in volume could declare the disposal of a component making it a costly affair. In the current effort, a hybrid approach of additive and subtractive processes was adopted to repair material removal and plastic deformation defects. Laser metal deposition and welding were the additive processes chosen for repair of the defects, and mini-tensile testing was employed as the characterization technique. A two-way statistical analysis was performed on the outputs obtained from the testing to establish the superiority in repair capability for each of the additive processes. The avg. yield strength obtained from laser repaired samples was found to be around 25% more than weld repaired specimens and avg. grain size for the laser repaired specimens was found to be approximately 1/3rd the size from weld repair.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design for Manufacturing and Assembly

2014;():V004T06A011. doi:10.1115/DETC2014-34223.

Nowadays, large monolithic machined parts are increasingly used in aerospace industry. Machining-induced residual stress usually dominates thin part’s distortion. The resultant part input with mutual corresponding distortion pattern and inner residual stress has an impact on subsequent assembly geometric and stress variation of thin-walled structure. Final pre-stressed assembly state further affects product functionality. This paper illustrates a simulated methodology combining automatic scripting technique with a FEA tool to reveal the assembly variation’s distribution and pattern caused by the fluctuation of machining-induced residual stress. A typical assembly unit case in aircraft is investigated by applying the proposed methodology, more specifically, considering the uncertainty of the dominant shear stress via simulating the normal distributed weights of basis functions. Moreover, the quantitative effect of introducing residual stress is explored to examine the applicability of traditional Method of Influence Coefficients, which constructs a sensitivity matrix of the linear relation between incoming part variation and output assembly variation using FEA. This study enhances the understanding of the effect of introducing residual stress into assembly and helps the statistical inference about both geometric and stress aspects.

Commentary by Dr. Valentin Fuster
2014;():V004T06A012. doi:10.1115/DETC2014-34271.

Micro two shot injection moulding (μtwo shot IM) is a manufacturing process capable of simultaneously replicating two polymeric parts and assembling them; removing the requirement for costly micro assembly. Endoscopes are used in medical environments to observe areas that are otherwise unobservable. μTwo shot IM has the potential to simultaneously replicate and assemble polymer lenses for endoscope imaging and assembling them to their required housing. In view of this, this paper contributes a case study part for application of μtwo shot injection moulding in the fabrication of an endoscopic micro optical component. This paper covers several aspects involved in the design of such a part. This novel design concept consists of an optical component and a housing component moulded sequentially on top of each other using μtwo shot IM. The lens component consisted of three lenses with a common base moulded as the first shot. The second shot moulded on onto the optical component was the housing component incorporating an external thread for interchangeability. From a material selection exercise it was concluded that cyclic olefin copolymer (COC) shall be used as the optical material and polyoxymethylene (POM) shall be used as the housing material. One major concern in the design of such a part is the deformation of the optical material by the housing material due to softening via heat transfer. Simulations of such a scenario were carried out and it was indicated that the functionality of the optical material shall not be compromised.

Commentary by Dr. Valentin Fuster
2014;():V004T06A013. doi:10.1115/DETC2014-34312.

Free-form surfaces can be machined continuously with minimum tool retractions and at the high speed by following a spiral tool path. This paper presents an improved planning method of the spiral tool path using eccentric parameters for machining free-form surfaces. The relationship between a 3D machined surface and the 2D circular region is established through the conformal mapping. In order to generate an even path, eccentric parameters are used in 2D parametric circular regions to optimize the path interval. The proposed method produces planar spiral segments as a diagonal curve between every two adjacent parametric tool paths. A 2D spiral tool path is gained by linking spiral segments in sequence. Inverse mapping of the 2D spiral tool path onto the machined surface generates the 3D spiral tool path. The main processes of the proposed method include reducing dimensions of free-form surfaces, calculating the eccentric parametric tool path, and generating the planar diagonal spiral tool path. Some applications are used to verify the proposed methods. The proposed method allows the start point to be arbitrary and generates more even tool paths than the existing methods by introducing the mapping distortion.

Commentary by Dr. Valentin Fuster
2014;():V004T06A014. doi:10.1115/DETC2014-34542.

With continued demands on high-quality and low-cost products, designers are increasingly required to explore the use of new materials and manufacturing processes. The design for manufacturability rules for unconventional materials and processes will be of great value to improve component manufacturability. Instead of going through years of trial-and-error practice to gain some “rule of thumb” design guidelines, this paper proposed a knowledge-based computational method for manufacturability constraint modeling (MCM) through process simulation, design of experiment, and data mining. With the input of geometric attributes for local critical features of a component, the pre-trained manufacturability constraint model will output the manufacturability prediction and the confidence of the prediction. The 2D visualization of the manufacturability prediction facilitates the interpretation by the human designers, and provides her with concurrent and intuitive manufacturability feedback and directed re-design suggestions. The preliminary result on mild steel stamping process demonstrated the feasibility of the method.

Commentary by Dr. Valentin Fuster
2014;():V004T06A015. doi:10.1115/DETC2014-34740.

Eliciting knowledge about dimensional variability and influential parameters is crucial in competitive manufacturing. Moreover, this knowledge needs to be generalized and transferred into a practical tool box that design engineers can use as a decision basis in the early phases of product development processes when design flexibility is high and the ‘cost of learning’ is low. This paper introduces Flatness Limit Curves, a new Design For Manufacturing (DFM) tool, which is aimed at assessing cross-sectional distortions relative to dimensional tolerance requirements in bending operation. Analytical relationships are derived from the theoretical basis of continuum mechanics, applying the deformation theory of plasticity to plane stress sheet metal problems. The theoretical results are compared with experimental results obtained for hollow AA7xxx extrusions, which were formed in an industry-like rotary stretch bender in a controlled laboratory environment. The solutions are then structured and organized into a set of limit curves for assessing nominal flatness of the exterior of the cross section after bending. The associated variability may also be estimated by varying key input parameters to the tool (dimensional accuracy and material quality) within the capability ranges of the upstream process.

Topics: Design
Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design for Quality, Reliability, and Cost

2014;():V004T06A016. doi:10.1115/DETC2014-34732.

The traditional Monte Carlo Simulation (MCS) approach can provide high reliability analysis accuracy, however, with low computational efficiency. Especially, it is computationally expensive to evaluate a very small failure probability. In this paper, a Subset Simulation-based Reliability Analysis (SSRA) approach is combined with the Multidisciplinary Design Optimization (MDO) to improve the computational efficiency in the Reliability based Multidisciplinary Design Optimization (RBMDO) problems. Furthermore, the Sequential Optimization and Reliability Assessment (SORA) approach is utilized to decouple the RBMDO into MDO and reliability analysis. The formula of MDO with SSRA within the framework of SORA (MDO-SSRA-SORA) is proposed to solve the design optimization problem of hydraulic transmission mechanism.

Commentary by Dr. Valentin Fuster
2014;():V004T06A017. doi:10.1115/DETC2014-35099.

This paper presents a novel method for adaptive slicing based on volumetric error considerations for Layered Manufacturing (LM). In the general LM process uses constant layer thickness throughout the part height which leads to poor surface finish at inclined surfaces. Therefore, adaptive slicing was proposed to control the surface roughness by adaptively selecting the layer thickness based on surface finish at a particular angle or slope of the surface. Most of the researchers used the cusp height concept for adaptive slicing. However, limitation of cusp height based adaptive slicing procedure is that, it does not have any direct control on volumetric error and it is quite possible that with a very little variation in cusp height a large variation in volumetric error may occur on steep slopes of surface. In the proposed work an algorithm is developed and implemented for adaptive slicing to control/select layer thickness based on user specified volumetric error/loss. A model is developed to calculate volumetric loss for the particular layer considering the geometry of the model.

Topics: Manufacturing , Errors
Commentary by Dr. Valentin Fuster
2014;():V004T06A018. doi:10.1115/DETC2014-35102.

The prediction of geometric variation and its consequences is one important aspect of product development. For welded assemblies it has been shown that positioning errors of the parts prior to welding affects the weld-induced distortion. Therefore, to accurately predict geometric variation in welded assemblies, variation simulation and welding simulation need to be performed in combination. This is usually a very time consuming task, and therefore, the relatively fast SCV-method is utilized. This method is used to calculate welding distortion when positioning errors are present and it consists of the following three steps: 1) a steady state computation of the thermal distribution during welding, 2) the melted zone along the full joint is encapsulated by sweeping a two-dimensional convex hull along the weld gun path, and 3) a uniform temperature is applied to all nodes inside this zone. The two-dimensional convex hull is computed so that when swept along the weld path, it will encapsulate the melted zone from the steady state temperature computation. The weld-induced distortion is obtained from the elastic volumetric shrinkage. In this article the focus is on the first step in this method; the temperature distribution computation. The positioning error can cause the connecting parts to have varying distances to each other at the joint, which cause the melted region to vary along the weld path. Therefore, it is not sufficient to capture the steady state temperature distribution at only one location. Depending on the geometry surrounding the weld path, several locations may be needed. In this new approach, the two-dimensional convex hull that is to be swept along the weld path, can vary along the weld path, and is computed from an interpolation of the multiple two-dimensional convex hulls obtained from the multiple steady state temperature computations. A comparison of the melted region using transient temperature calculation, a single steady state temperature calculation and this new approach has been made. Furthermore, the implication on distortion calculation has been studied.

Commentary by Dr. Valentin Fuster
2014;():V004T06A019. doi:10.1115/DETC2014-35273.

Tolerances are specified by a designer to allow reasonable freedom by a manufacturer for imperfections and inherent variability without compromising performance. T-Map is a hypothetical Euclidian point space model which describes all possible variations constrained by design or machining tolerances. The size and shape of T-Map reflects all variational possibilities for a target feature. According to ASME Y14.5M standard, tolerances are dimensional or geometric, and geometric tolerances are divided into different classes. T-maps have been created for all types of geometric tolerances with Primitive T-Map Elements. In this paper we have reviewed the basic ideas of T-maps, the reason it has been built, and the contribution it can have in design and manufacturing. It is then followed by a library of T-maps created for all Tolerance classes with brief description for each one.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design for Supply Chain

2014;():V004T06A020. doi:10.1115/DETC2014-34194.

Measuring quality in design-driven innovation is part of the larger subject of product design, supply chain management and new product development (NPD). In other words, better design and supply chain integration increase the efficiency and effectiveness of the production development process. In this work, I have studied the role of understanding the needs of customers and design approaches for new products through a combination of customer feedback and participation of designers in the first phase of new product development. Furthermore, I discuss why the incorporation of both designers and customer needs is important to design-driven innovation. In the second phase of this study, I present several case studies in terms of supplier-buyer relationships in order to find a solution that achieves a long-term relationship (the alliance-star model) in new product development, which is a crucial problem in the Blue Ocean Strategy. Finally, by presenting the CDFS (Customer-Designer-Firm-Supplier) strategic model, we show schematically the integrated-comprehensive process approach for creating a new innovative product from the concept phase through to the end of Product life cycle. This model presents the process of new innovation, which can ensure added value during Product life cycle.

Topics: Design
Commentary by Dr. Valentin Fuster
2014;():V004T06A021. doi:10.1115/DETC2014-34512.

Due to the nature of the manufacturing and support activities associated with long life cycle products, the parts that products required need to be dependably and consistently available. However, the parts that comprise long lifetime products are susceptible to a variety of supply chain disruptions. In order to minimize the impact of these unavoidable disruptions to production, manufacturers can implement proactive mitigation strategies. Two mitigation strategies in particular have been proven to decrease the penalty costs associated with disruptions: second sourcing and buffering. Second sourcing involves selecting two distinct suppliers from which to purchase parts over the life of the part’s use within a product or organization. Second sourcing reduces the probability of part unavailability (and its associated penalties), but at the expense of qualification and support costs for multiple suppliers. An alternative disruption mitigation strategy is buffering (also referred to as hoarding). Buffering involves stocking enough parts in inventory to satisfy the forecasted part demand (for both manufacturing and maintenance requirements) for a fixed future time period so as to offset the impact of disruptions. Careful selection of the mitigation strategy (second sourcing, buffering, or a combination of the two) is key, as it can dramatically impact a part’s total cost of ownership.

This paper studies the effectiveness of traditional analytical models compared to a simulation-based approach for the selection of an optimal disruption mitigation strategy. A verification case study was performed to check the accuracy and applicability of the simulation-based model. The case study results show that the simulation model is capable of replicating results from operations research models, and overcomes significant scenario restrictions that limit the usefulness of analytical models as decision-making tools. Four assumptions, in particular, severely limit the realism of most analytical models but do not constrain the simulation-based model. These limiting assumptions are: 1) no fixed costs associated with part orders, 2) infinite-horizon, 3) perfectly reliable backup supplier, and 4) disruptions lasting full ordering periods (as opposed to fractional periods).

Commentary by Dr. Valentin Fuster
2014;():V004T06A022. doi:10.1115/DETC2014-34957.

This paper examines the distribution network for a manufacturing business looking at aspects of sustainability including economic, environmental and social considerations. The problem is initially approached mathematically, then applied experimentally using a specialist software, Orion-pi. A real life business, Rettig ICC, is used as a case study to show how the theory could be applied to a practical example and would provide financial savings, reduced carbon emissions and lay the groundwork for a more ethical business strategy. The results show it will be a financially and environmentally positive move to decrease the current activity at Birtley and operate an additional smaller distribution centre at Coventry.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design of Product-Service Systems

2014;():V004T06A023. doi:10.1115/DETC2014-34175.

This paper analyzes design equilibrium in a concurrent product-development project using the results from behavioral game theory. In this study, a project consists of a team of three engineers who represent three product-development stages: product design, material selection, and process selection. Product-development tasks are globally distributed, and engineers are allowed to independently make product-development decisions (i.e., non-cooperative design). In addition, the engineers are evaluated according to the outcomes of both individual and team product-development tasks. When multiple design equilibria exist, but a dominant design equilibrium does not, the past behavioral-game-theory studies indicate that design equilibrium may be reached under two conditions. In the first condition, one engineer is allowed to announce his/her intended alternative even though he/she does not need to actually choose the announced alternative. In the second condition, one engineer is selected to make his/her choice first but the other engineers do not know what that choice is. Sensitivity analysis indicates that a wide variety of design equilibria will emerge depending on how engineers are evaluated.

Commentary by Dr. Valentin Fuster
2014;():V004T06A024. doi:10.1115/DETC2014-34186.

To compete in the global market, many manufacturers are moving towards mass customization of products. This allows the manufacturer to take advantage of the high volumes found in mass production while still manufacturing products that fit the needs of individual customers. In order to effectively implement mass customization principles in production, the manufacturers must rely on some form of configuration management to keep track of the large amount of domain knowledge that is involved. The purpose of this paper is to present a review of existing configuration management practices and why they are necessary in today’s economy. This includes a case study of the configuration management and configuration change practices of a major automotive OEM. Based on the results of the case study, the authors present a series of recommendations to increase the effectiveness of the OEM’s change management practices.

Commentary by Dr. Valentin Fuster
2014;():V004T06A025. doi:10.1115/DETC2014-34302.

The diversity of costumer’s needs requires manufacturers to provide a complex package of product and service. In contrast to traditional matured methods used for product design, Product/Service Systems (PSS) design still has a large room for development because of three following core research challenges: 1) development of a common shared structure to represent and understand PSS’s elements and their relations; 2) systematic modelling approaches to formulating design problems; and 3) holistic consideration of social, technological, economic and ecological elements.

This paper aims to propose a novel framework for PSS design by addressing three issues above. The proposed framework is derived step-by-step from a natural language description of PSS environment using Environment-Based Design (EBD) methodology. The proposed framework attempts to accommodate the recursive scenarios in PSS design along with PSS lifecycle. The PSS environment will be firstly analyzed through a question-asking strategy. Besides, a set of graphical tools will be presented to support the development of framework, such as product-environment system, performance network, and conflict map. A case study, concerning the service design of intellectual property protection in collaborative product development, will be presented to illustrate the proposed framework.

Commentary by Dr. Valentin Fuster
2014;():V004T06A026. doi:10.1115/DETC2014-35188.

Recent trends towards service orientation make manufacturing, especially in developed economies, to move into a more service oriented strategy. One solution is to fulfill customer requirements by a product and its after-sales services. However, the actual impact of this transformation on manufacturers has never been explored. This study aims to understand how evolution of service in terms of service-width and length takes place over time, and how it impacts on the manufacturer and is impacted from it. We carry out a longitudinal case-based study on a particular service family (iTune) in consumer electronics using Pearson correlation and linear regression using SPSS software package. Considering consistent intention to improve existing ones and introduce new services, following results are gained: (1) Manufacturing with higher research and development capabilities are expected to have great potential to have strong after-sales portfolio both in terms of service-width and length. A strong portfolio in this type of manufacturing is expected to bring economic advantage. (2) Manufacturing with higher liabilities is expected to have more economic advantage in increasing service-width. (3) Manufacturing with robust infrastructure are expected to have more economic advantage in increasing service-length.

Topics: Manufacturing
Commentary by Dr. Valentin Fuster
2014;():V004T06A027. doi:10.1115/DETC2014-35446.

Products evolve over time to follow new customer needs and technologies. Although the proper estimation of future products has been regarded as a critical issue for business success, it has not been widely discussed in an analytical way. Focusing on the evolution of a product family, this paper aims to develop a dynamic model which can effectively show the structural changes of a product family over time. The proposed model is based on a network representing the structural architecture of a product family. This model employs the concept of Fitness Model [1], where nodes in a certain system have their own fitness values to represent the degree of gaining edges with new nodes. The dynamic model proposed in this paper would be a basis for the estimation of product family evolution; it is potentially effective to simulate possible future structures of a product family according to different platform leveraging strategies.

Topics: Dynamic models
Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Design of Thermal and Energy Systems

2014;():V004T06A028. doi:10.1115/DETC2014-34020.

This paper examines the gasification of woody biomass pellets and torrefied wood pellets at different temperatures using air or CO2 as the gasifying agents. The woody biomass pellets were pyrolyzed and gasified in a controlled reactor facility that allowed for the determination of sample weight loss as a function of time from which the kinetics parameters were evaluated. The experimental facility provided full optical access that allowed for in-situ monitoring of the fate of the biomass pellets and the release of gas phase under prescribed high temperature condition. Pellet sample of known weight was placed in a wire mesh cage and then introduced instantly into the high temperature zone of the reactor at known temperature and surrounding gas composition as gasifying agent. The weight loss as function of time was examined for different gasification temperatures ranging from 600–950°C using air or CO2 as the gasifying agent. Significant differences in the weight loss were observed to reveal the fundamental pyro-gasification behavior between the wood and torrefied wood pellets. The results show enhanced gasification with air at low to moderate temperatures while at high temperatures the oxygen evolved from CO2 provided a role in oxidation. The calculated activated energy was lower for woody pellets than torrefied wood pellets and it was lower with air than CO2. These kinetic parameters help in modeling to design biomass gasifiers and combustors for increased conversion efficiency and performance using biomass or municipal solid waste pellets.

Commentary by Dr. Valentin Fuster
2014;():V004T06A029. doi:10.1115/DETC2014-34102.

The use of numerical simulation methods for the Cultural Heritage is of increasing importance for the analysis, conservation, restoration and appreciation of works of art. This is particularly important when their preservation and planned maintenance is the primary aim [1, 2]. King Tutankhamen’s gallery at the Egyptian museum is chosen for our study. The conservation of such artworks requires precise control of the indoor microclimatic conditions. Thus, a suitable HVAC system with reliable control is often necessary for a museum, to maintain acceptable indoor thermal-hygrometric parameters and air velocity and also to minimize the deviations of these parameters from the design values. An investigation of airflow characteristics inside King Tutankhamen’s gallery at the Egyptian museum is studied. The effect of visitors within the gallery space is discussed. Lighting is mainly neglected and its effect is shown in a limited procedure. The variability of inlet air velocities and the grills location in the gallery is studied to achieve a better understanding of the closest solution for air distribution within the gallery.

Commentary by Dr. Valentin Fuster
2014;():V004T06A030. doi:10.1115/DETC2014-34483.

Toward realizing a low-carbon society, a thermoelectric generator (TEG) is promising for energy harvesting by generating electricity from thermal energy, especially waste heat. While there are various technologies available for energy recovery, one of the strengths of TEGs is to retrieve usable energy from waste heat whose temperature is as low as 200∼300 degrees Celsius. Yet, the conversion efficiency of the current thermoelectric materials remains low at 5∼10%, which makes it difficult to diffuse TEGs in our society. In order to clarify required performances of TEGs to diffuse them in the future, this paper aims to assess the life cycle CO2 emissions (LCCO2) and life cycle cost (LCC) of TEGs based on several product lifecycle scenarios, each of which assumes different future situations in, e.g., conversion efficiency of TEGs. In this paper, we focus on TEGs for passenger automobiles since a range of the temperatures of their exhaust gas is suitable for TEGs. Additionally, we focus on bismuth telluride (Bi-Te) materials to develop TEGs since they have already been available for commercial use. A case study of installing Bi-Te TEGs in passenger automobiles is carried out. The region of interest is Suita City, Osaka, Japan. By describing two scenarios that assume different conversion efficiency of thermoelectric materials, we compare assessment results from the viewpoints of LCCO2 and LCC. The results reveal that using TEGs has the potential to reduce CO2 emissions of the city by 0.07∼0.30%. It is also shown that the TEG cost needs to be drastically reduced to make the usage of TEGs profitable.

Commentary by Dr. Valentin Fuster
2014;():V004T06A031. doi:10.1115/DETC2014-35056.

Beyond the usual energy efficiency of buildings, industrial energy efficiency involves major politico-economical and environmental challenges, among which the emergence of eco-industrial parks and symbioses. Solving these challenges require reliable methodologies and tools. Having interviewed some major industrial energy stakeholders, it appeared that despite of their motivation, energy efficiency projects were not really successful because of the difficulty in identifying adequate simulation methodologies and/or tools. Moreover, in spite of multiple research projects in industrial energy efficiency, it seems that previous research works do not sufficiently support a systematic and integration view.

In this paper, we propose a critical review and a categorization of energy efficiency research methodologies and tools. The analysis of these solutions results in the building of an inventory of more than 50 modeling and simulation software tools. Furthermore, a positing matrix is designed in order to map energy efficiency solutions according to identified granularity levels of industrial systems as well as their marketing maturity level.

Commentary by Dr. Valentin Fuster
2014;():V004T06A032. doi:10.1115/DETC2014-35202.

Building insulation is considered as a solution to reduce the energy cost for both residential and commercial buildings. However, determining the best combination of insulation materials that result into the lowest total ownership cost is now becoming a bigger challenge. Various factors influence the efficiency of heat transfer within a room including geometry and size of the room, ambient temperature, heat and sink sources presented inside the building, type of insulation materials, etc. The aim of this paper is to develop an optimization-based decision making tool to help house owners select the best combination of given insulation materials considering all these factors. The purpose of design approach adopted in this paper is to minimize total ownership cost while providing the required heating in the building. The SQP, Quasi-Newton, line-search algorithm was used to obtain the optimized thermal conductivity values for the combination of insulation material to be used in the walls, floor, ceiling, window and the door of a room, along with the width of the air gap to be kept. The results help in deciding what combination of insulation material will achieve the required heating for the house owner while keep the total cost incurred to be minimum.

Commentary by Dr. Valentin Fuster
2014;():V004T06A033. doi:10.1115/DETC2014-35248.

Solar power systems are becoming increasingly popular due to the fact that solar power can offer time and money saving solutions for off-grid and grid-connected homes, cabins, and businesses with clean and affordable energy. However, there are still significant opportunities to reduce the cost of solar power systems by optimizing system design. We employ system modeling and simulation methods to compare a commercial rooftop solar system with a new concept for the same application, namely Mega Module system. In order to accomplish this, a solar power system’s lifecycle is divided into three phases, namely manufacturing, installation, and maintenance. Specifically, a SysML-based conceptual model was first constructed, based on which, Arena simulation models were built for three phases of the two systems. Then, we performed input analysis on data collected onsite for the two systems, and output analysis of the theoretical seconds/watt of all three phases based on reasonable assumptions. The results of the simulation study indicate that although it increases the manufacturing time, the Mega Module system saves a significant amount of time in the installation phase and a relatively small amount of time in the maintenance phase, and thus can be more cost-effective in the long term. The case study further demonstrates the feasibility and potential to reduce costs of product-service systems by quick installation and optimization using system modeling and simulation methods.

Commentary by Dr. Valentin Fuster
2014;():V004T06A034. doi:10.1115/DETC2014-35528.

Building occupants are considered as a major source of uncertainty in energy modeling nowadays. Yet, industrial energy simulation tools often account for occupant behavior through some predefined scenarios and fixed consumption profiles which yield to unrealistic and inaccurate predictions. In this paper, a stochastic activity-based approach for forecasting occupant-related energy consumption in residential buildings is proposed. First, the model is exposed together with its different variables. Second, a direct application of the model on the domestic activity “washing laundry” is performed. A number of simulations are performed and their results are presented and discussed. Finally, the model is validated by confronting simulation results to real measured data.

Commentary by Dr. Valentin Fuster
2014;():V004T06A035. doi:10.1115/DETC2014-35663.

The renewable energy is a promising field, which shows a lot of potential for future energy solutions. The design of the blade shows a lot effects on the efficiency of the wind turbine, and the design parameters governs the performance characteristics. This paper addresses a number of innovative blade designs that was developed by alterations made to the existing conventional straight blade. These blades were extensively studied using computational fluid dynamics (CFD) software, and showed promising results, which was the motive behind this study. We are designing an experiment to study small scale wind turbines, which will enable us to gather data that will explain some differences in power and torque output. These steps will help us to come to a better understanding of some aerodynamic aspects that will impact the performance of each individual blade design. The comparing criteria for this study was the torque generation at the axes of rotation, which can be translated to several parameters, such as energy output, using some theoretical basis equations.

Commentary by Dr. Valentin Fuster
2014;():V004T06A036. doi:10.1115/DETC2014-35664.

The design and build of a Thermo-gravimetric analyzer (TGA) is discussed in this paper along with the preliminary data obtained. The TGA was designed for biomass pyrolysis and gasification. In the design it was taken in consideration decreasing the size as possible so as to decrease the area subject to heat losses as possible and to be capable of reaching high temperatures sufficient for both pyrolysis and gasification. The TGA was then tested using carbon dioxide and calculations for the rate of mass converted and conversion rate were carried out.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Integrated Product and Process Development

2014;():V004T06A037. doi:10.1115/DETC2014-34577.

The function-structure (F-S) Map expresses the high-level structure of a design. It is often used in the early stage of conceptual design and serves as the starting point for a number of design tools like quality function deployment, failure mode and effects analysis, and more. On the other hand, in designing risk products whose failure can result in serious damage to the quality of human health or the society, the designer often uses tools like failure mode and effect analysis or fault tree analysis to detect weaknesses in design before the products are shaped. Failures, nonetheless, take place and cause negative impact to the society. It is then that the designer or other experts review the design to find flaws in the failure analysis tree or find elements or links in the graph that the designer overlooked. In other words, pre-production failure analysis is limited to the designer’s knowledge and insight. This paper proposes a way to make use of failure knowledge with past accident cases by constructing the F-S Map for the failed products and storing the information in a failure database. Designers can then compare the F-S Map for new products with linked representation of past failure cases and realize scenarios of failure he did not recognize or have to design carefully.

Topics: Failure
Commentary by Dr. Valentin Fuster
2014;():V004T06A038. doi:10.1115/DETC2014-34827.

This paper proposes a new optimization-based project planning method that aims at a Pareto-optimal of the potential product performance of designed product and a project failure risk. A task option model is introduced for risk assessment of option-based project management. As its planning includes a number of various design variables and various evaluation indices, in order to solve such a complicated problem with a reasonable computation cost, this research separates the optimization problem into two phases, i.e., (i) defining of process architecture and organization structure and (ii) scheduling of resource allocation into activities. This paper demonstrates its application to a student formula design project. A proposed optimization method facilitates a project manager to explore various process plans with assessing their risks.

Commentary by Dr. Valentin Fuster
2014;():V004T06A039. doi:10.1115/DETC2014-34884.

This work presents the automation of high-accuracy CNC tool trajectory planning from CAD to G-code generation through optimal NURBs surface approximation. The proposed optimization method finds the minimum number of NURBS control points for a given admissible theoretical cord error between the desired and manufactured surfaces. The result is a compact part program that is less sensitive to data starvation than circular and spline interpolations with potential better surface finish. The proposed approach is demonstrated with the tool path generation of an involute gear profile.

Commentary by Dr. Valentin Fuster
2014;():V004T06A040. doi:10.1115/DETC2014-35284.

In modern automotive manufacturing the data associated with the products and the assembly processes required to build a car are not intelligently linked. This becomes problematic when trying to efficiently create best practice templates for assembly processes because the procedure for linking these best practice assembly processes with vehicle components becomes a daunting task. This research is aimed at the development of a decision support system and cyber infrastructure for efficiently linking product information and process information. Specifically, tools are developed to link product and process information in the automotive industry. The goal of this research is to develop and encode rules to guide the linking of product and process information. These rules are formed from historical data and provide suggestions to process planners as to which variants of parts can be assigned to the same standardized set of assembly instructions which exist as process sheet templates. The part data used consists of a standard text description of the part, the bounding box coordinates for all possible installation locations of the part, a unique identifier for the part, and a logic string which defines valid vehicle configurations such as platforms, models, and options for which the part is valid. A portion of this data is analyzed and used as the basis for development of the part grouping rules. Each rule will compare two parts with respect to the relevant part data and determine whether the two parts are capable of being assigned to the same process sheet. The development of the rules is discussed along with examples, followed with a discussion regarding the implementation of the rules into a prototype system. The rules are tested against part data not used in the development process, and a discussion of the results is presented. The paper concludes with conclusions drawn from testing of the rules and a discussion of future work.

Topics: Manufacturing
Commentary by Dr. Valentin Fuster
2014;():V004T06A041. doi:10.1115/DETC2014-35500.

Problem formulations in natural language imply imprecision, ambiguity, incompleteness, conflict and inconsistency between requirements in a design problem. Recursive Object Model (ROM) based problem formulation in conceptual design extracts complete product requirement from design problems structured initially in natural language. Since ROM carries certain semantic and syntactic information implied in natural language, it is used to formulate a design problem through a question asking approach. The scope of this paper is to present an updated algorithm, question templates, rules and detailed procedures to ask generic questions based on ROM representations. Generic questions are needed for the clarification and extension of the meaning of a design problem in order to overcome the imprecisions, ambiguities, conflicts and inconsistencies of problem descriptions in natural language. The updated algorithm, question templates, rules and detailed procedures for asking generic questions are used in a case study to formulate the development of a Total Quality Management system (TQMS).

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Life Cycle Decision Making

2014;():V004T06A042. doi:10.1115/DETC2014-34559.

Recent manufacturing research has focused attention on methods for improving the sustainability performance of high-volume manufacturing. Most manufacturing businesses operate at the small to medium scale, however, and would benefit from the transfer of knowledge gained from this work to lower volume production. To demonstrate an example of this knowledge transfer, the sustainability performance of two manufacturing strategies is investigated for small-scale caddisfly jewelry production. Control over the aesthetics of the end product is an important feature of jewelry manufacturing. In this case, however, increasing product quality control can have life cycle impacts which are unaccounted for in typical decision making. To make a decision between two caddisfly jewelry manufacturing strategies, a comparative gate-to-gate sustainability assessment was performed. The method combines life cycle inventory analysis, life cycle costing, and worker injury risk assessment to develop a holistic comparison encompassing the three pillars of sustainability. The assessment revealed tradeoffs between environmental impacts, costs, and social impacts for the two scenarios. Thus, hierarchical importance of the three sustainability pillars is needed to make stakeholder decisions. In this small-scale manufacturing case, such decision-making is found to be primarily driven by the personal values of the business owners.

Commentary by Dr. Valentin Fuster
2014;():V004T06A043. doi:10.1115/DETC2014-34584.

The research context is about eco-design improvement that focuses on modifying an existing product for reducing its environmental impacts. In this context, engineers may propose various design concepts that can potentially make the product more environmentally friendly. At this point, the research problem is how to assess environmental impacts of each concept given the uncertainty of design information at the conceptual design stage. To address this research problem, the trapezoidal fuzzy numbers are first applied to capture imprecise design information. Then, the centroid concept is applied to model different views of imprecision (i.e., pessimistic, balanced and optimistic) associated in fuzzy impact assessment. Accordingly, a decision scheme is developed for assessing different design concepts and suggesting the potential areas of a design concept to reduce environmental impacts. In an application, a coffee maker has been decomposed and analyzed to propose three possible concepts for eco-design improvements. These three concepts are then assessed by the proposed method of this paper to demonstrate the methodical workflow and utility that assists engineers to make eco-design decisions at the early design stage.

Commentary by Dr. Valentin Fuster
2014;():V004T06A044. doi:10.1115/DETC2014-35183.

Adaptable products can meet different functional requirements in the product life cycle by adding or replacing function modules of the products. Product’s architecture builds relationships of functional modules to support feasibility of the adaptable products to be upgraded based on users’ needs. A final adaptable product is formed by the combination of different functional modules. This paper introduces a quantitative measure of product adaptability based on the product architecture, interface complexity and operation ability. Design efficiency of module interactions is introduced to evaluate product adaptability based on the design solution and related operation constraints of interactions. An electric vehicle is improved for the adaptability based on the proposed evaluation method.

Commentary by Dr. Valentin Fuster
2014;():V004T06A045. doi:10.1115/DETC2014-35195.

The motivation behind this work is to integrate economic and environmental sustainability into decision making at the early phases of design through the development of a hierarchical concept selection method. Life Cycle Assessment (LCA) is a frequently implemented technique used to assess the environmental impacts of products, but it does not provide a simple means for including preference at different levels that can be used for comparison across design alternatives. A method is proposed to accommodate this issue expanding the Hypothetical Equivalents and Inequivalents Method (HEIM) to handle multi-level and multi-attribute trade-offs. The selection of a coffee maker design is used as an example to illustrate the implementation of the method with actual LCA results. The example provides valuable insights into how preferences may be elicited at different hierarchical levels and then combined to create a single utility score that represents to what extent each design alternative is preferred by the decision maker.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Sustainability of Industrial Systems (Special Session)

2014;():V004T06A046. doi:10.1115/DETC2014-34340.

Nowadays, the environmental issue has become increasingly important and has taken a leading role in the product design process. The product sustainability pass through the use of specific software tools supporting the design phase. Their integration, to build up a platform, is a key aspect toward the implementation of an effective eco-design approach.

Even if the approaches presented in literature to create an eco-design platform aim to integrate environmental aspects during the design process, a proper tools integration is not existing.

To overcome these limitations, the paper presents an eco-design platform in which tools for the improvement of the product environmental characteristics are contained. The tools of the platform are used to calculate the environmental impact of a product for each product life cycle phase: manufacturing, transportation, use and End of Life. The platform is completed by a tool containing the eco-design guidelines, also specific for the industrial sector of the company, used to suggest the designers how to improve the product eco-sustainability.

The end users of the platform consist of designers from the design office but also from every department relevant for the project, mainly R&D, production, purchasing department, and quality. In particular, the following roles have been considered as users: designer, product manager, environmental manager and buyer.

Designers and company experts use the same workspace, made of different tools. They can detail all the product life cycle phases, quantify the product performances, modify its characteristics and verify the improvements obtained without change the traditional design process in a radical way.

Topics: Green design
Commentary by Dr. Valentin Fuster
2014;():V004T06A047. doi:10.1115/DETC2014-34557.

While environmental impact analysis is standard in accordance with ISO 14040:2006 using life cycle assessment software, such as GaBi and SimaPro, software tools supporting broader sustainability assessment are limited. Recent research has developed methods for sustainable manufacturing assessment and has led to unit manufacturing process models that can be used to quantify sustainability metrics. In spite of these advances, engineering designers must apply such methods in an ad hoc manner, which increases engineering analysis time and limits the utility of sustainability assessment in early design. Thus, manufacturing process models and supporting software tool are developed to assist design for manufacturing efforts pursuing sustainability performance improvement. The software is constructed using Visual Basic to create a graphical user interface for an MS Excel calculation engine. Using unit manufacturing process models, a product sustainability assessment can be generated by chaining together a sequential manufacturing process flow. In this way, cradle-to-gate assessments can support decisions made during product, process, and supply chain design. The method combines upstream inventory analysis and in-house unit process modeling to perform cradle-to-gate sustainability assessment. The utility of the approach is demonstrated for the assessment of an aircraft-like metal product assembly.

Commentary by Dr. Valentin Fuster
2014;():V004T06A048. doi:10.1115/DETC2014-34882.

Life Cycle Assessment (LCA) is a methodology to assess environmental performances of products throughout their life cycles. Traditionally, LCA-based decision-making focuses on environmental impacts, excluding customer expectations and economic considerations. Moreover, it usually uses generic data while environmental performances of industrial systems often depend on local contexts. The aim of this paper is to provide a comprehensive framework to identify the solution most adapted to a specific context, considering environmental, economic and commercial aspects. First, environmental performances of competing products are compared thanks to LCA. A sensitivity analysis highlights influential parameters on which operational scenarios are built. Costs are then incorporated into a set of exploitation scenarios.

Second, matrix-based approach is used. Products are ranked according to several client profiles. The most suitable solution for a given context is identified.

This framework is applied on three burners for forge furnaces. Results show that client profiles and operational contexts (namely client expectations, location and resources availability and costs) affect choices.

Commentary by Dr. Valentin Fuster
2014;():V004T06A049. doi:10.1115/DETC2014-34960.

In this paper, we present ViSER, an interactive visual analytics platform that visualizes supply chain data for enabling eco-conscious redesign. ViSER provides a visualization dashboard consisting of multiple mutually coordinated views that provide different perspectives on a particular supply chain scenario. Our platform allows users to visualize a change propagation metric associated with a particular redesign path. Hence, the user can balance the advantages of a redesign opportunity with the risk associated with its effect on the rest of the supply chain. Furthermore, ViSER offers lifecycle data representations that inform users’ decisions particularly in the context of eco-conscious re-design. Coupling such environmental data with graph-based visualizations of product architecture, ViSER provides a novel decision platform for designers with a range of expertise levels. To demonstrate its utility, two use-case scenarios, from both a novice and expert perspective, are presented in detail.

Topics: Supply chains
Commentary by Dr. Valentin Fuster
2014;():V004T06A050. doi:10.1115/DETC2014-35351.

The cylindrical filters presently used in <1000 m2 drip irrigation systems are frequently clogged, increasing pressure loss and lowering the flow rate through the filters. This work investigates the mechanisms for this clogging and proposes an alternative filtration design that would enable both more reliable and lower maintenance filtering. This proposed system is compatible with existing drip irrigation systems and could be made inexpensively with plastic bottle manufacturing equipment. To compare the proposed design to off-the-shelf options, a drip irrigation test setup was built to measure the pressure loss across different filters as particles accumulated. These experiments confirmed that pleated cartridge filters, with high effective surface area, incurred lower pressure losses than cylindrical filters. These tests revealed that the greatest reason for clogged performance was that filtered particles (not the cartridge filter itself) eventually restricted the flow of water through the system. This inspired the redesign of the filter housing such that the housing extended far below the filter, providing a catch basin away from the filter for the particles to settle. Fixing the filter independently of the bottom casing significantly improved the overall performance of the filtration system, reduced the maintenance requirement necessary from the user, and would enable inexpensive manufacturing via blow molding. This paper experimentally demonstrates that the cartridge filter inside the redesigned housing can filter out over 2 kg of sand while maintaining less than a .03 bar pressure drop across the filter at a flow rate of 25 l/s.

Commentary by Dr. Valentin Fuster

19th Design for Manufacturing and the Life Cycle Conference: Sustainable Design and Manufacturing

2014;():V004T06A051. doi:10.1115/DETC2014-34110.

Environmental performance of the abrasive flow machining (AFM) process is currently not well understood. Its flexibility as a manufacturing process has only recently been realised in SMEs (Small to Medium Enterprise) as a feasible automated alternative to deburring and polishing of complex geometry by hand, and as an alternative to honing and grinding using semi-automated machinery. [1–3]

Economic benefit is still the main driver in the commercial uptake of environmentally-sustainable technologies [4, 5]; despite AFM’s known flexibility and capability, this paper presents systematic research by focusing on AFM including, 1) assessing and comparing the requirements of competing processes (values sourced from [6]), 2) their power consumption, 3) operating conditions, 4) cost of pre-requisite ancillary equipment and 5) embodied energy and recyclability of machine structures and consumables. Three workpiece scenarios are laid out (distinguished by feature-count, processing time, tolerance-demands and setup-count) for comparison purposes — the trade-off between environmental and economic cost is described with reference to industrially-significant quality measures such as repeatability, accuracy, precision and uniformity. Key findings in this research include the comparatively high energy demand from natural gas-fired warm air blow-heaters, a requirement for the heating of spaces for human labour activity. Performance is shown to be limited by design — the AFM machine in this study operates with only an additional 22% of current between idle mode and production mode [7] suggesting sub-assembly redesign may be of benefit. To conclude, the AFM process offers a clear route to sustainable part-finishing, low-maintenance and high potential for ‘greening’ considering factors in addition to running cost.

Commentary by Dr. Valentin Fuster
2014;():V004T06A052. doi:10.1115/DETC2014-34317.

Although a large number of research activities have been conducted for sustainable product development, it is not easy to find a practical method applied in sustainable product design as there are many uncertain factors existed in particular problems faced in different phases of product development. Based on reviewed literature, it is found that it is necessary to have an optimization metric accompanied with uncertainty effects in product development. A model is proposed in this research to evaluate the effects of uncertainty in product life cycle. The goal is to quantify various types of uncertainty from internal and external sources to assess the design efficiency for mitigating undesirable effects of uncertainty. The design phase is aimed in the research to look at product parameters that are subject to change in the design process. Inaccuracy, indecision and imprecision are selected as information uncertainty levels to quantify the evolution of uncertainty. Using the proposed concept, the discrete-event simulation (DES) is used to model and evaluate scenarios to minimize design phase duration of a sustainable wheelchair. Suggested improvements are compared to search the optimal solution. The analysis and comparison of scenarios show ways to reduce design time by (1) revision of the design process, (2) breaking down the product into design details, and (3) providing a clear and technical definition of uncertainty to be mitigated. The model is also used to locate areas for sustainability improvement in the studied case.

Commentary by Dr. Valentin Fuster
2014;():V004T06A053. doi:10.1115/DETC2014-34743.

For sustainable manufacturing, energy consumption, air and waste emission, and environmental impact of product and process are analyzed in product and process development. The sustainability assessment is realized based on complete, structured information models of product, process and manufacturing resources, which are proposed in this paper. After analyzing the process of unit assembly and machining, two information models of unit assembly operation and unit machining process are given in UML representation. Besides the basic process parameters, the sustainable manufacturing related information such material consumption, energy usage, wastes and greenhouse air emission are also considered in the models. The manufacturing resource mode is core model to relate process and sustainability indicators. The resource information model of machining tool is proposed with process parameters and unit data of indictors. A sustainability assessment process is given in the end.

Commentary by Dr. Valentin Fuster
2014;():V004T06A054. doi:10.1115/DETC2014-34755.

A new perspective of dynamic LCA (life cycle assessment) is proposed with the predictive usage mining for sustainability (PUMS) algorithm. By defining usage patterns as trend, seasonality, and level from a time series of usage information, predictive LCA can be conducted in a real time horizon. Large-scale sensor data of product operation is analyzed in order to mine usage patterns and build a usage model for LCA. The PUMS algorithm consists of handling missing and abnormal values, seasonal period analysis, segmentation analysis, time series analysis, and predictive LCA. A newly developed segmentation algorithm can distinguish low activity periods and help to capture patterns more clearly. Furthermore, a predictive LCA method is formulated using a time series usage model. Finally, generated data is used to do predictive LCA of agricultural machinery as a case study.

Commentary by Dr. Valentin Fuster
2014;():V004T06A055. doi:10.1115/DETC2014-34846.

Descriptions of a product’s usage context are easily understood and often provide useful information for reducing energy consumption of products. Such descriptions help inspire concept generation, explore operational issues, and evaluate prototypes. Nevertheless, characterizing the usage context as a concise but comprehensive set of factors is not a trivial task. This paper presents a taxonomy and method for characterizing the usage context and its various scenarios as sets of factors relevant to energy consumption. The taxonomy defines a general usage context as a set of human, product and situational factors that can be specified individually to create unique scenarios. The method for identifying relevant factors is grounded by first assessing variables in the fundamental physical equations that govern product operation. Then, activity diagrams reveal the elements influencing user habits and procedures. The method is demonstrated through the example of an automobile and the results are compared with existing automobile studies.

Commentary by Dr. Valentin Fuster
2014;():V004T06A056. doi:10.1115/DETC2014-34942.

Idea of global sustainable development dictates greener machining processes. Cryogenic machining technologies enable cleaner, more energy efficient and less health hazardous process with possible lower production costs and higher productivity. In this paper, a 2D orthogonal cryogenic cutting process simulation model to predict the thermo-mechanical fields and the residual stress distribution remains in the machined surface of AZ31B magnesium alloy has been developed using ABAQUS FEM software. The proposed model can be applied to analyze influence of cutting condition parameters on the cutting forces and on the residual stress distribution in the machined surface and subsurface, which is a critical issue concerning energy efficiency and surface integrity of a cutting process.

Commentary by Dr. Valentin Fuster
2014;():V004T06A057. doi:10.1115/DETC2014-35091.

Modular product design (MPD) has attracted significant attention. The concept of sustainability has also received attention in view of the intensifying demands concerning environmental issues. Because the way a product or system is modularized can have implications on its sustainability, investigating MPD and sustainability jointly is important. To this intended joint investigation, we add the concept of a product’s key components. Mostly, product competitiveness depends strongly on a few key components; thus, we should logically design products with a concentrated consideration of their key components. However, to the best of our knowledge, only scant research addresses key components. Developing an optimal MPD method, which incorporates key components specification, is the primary motivation for this research. In this paper, we provide a sustainable modular product design approach. A graph-based clustering algorithm is offered to cluster components into modules. A module structure sustainability index (MSSI) is used to find an optimal sustainability module structure. A coffee maker case study is used to illustrate the proposed methodology.

Commentary by Dr. Valentin Fuster
2014;():V004T06A058. doi:10.1115/DETC2014-35200.

Injection molding (IM) has been the most widely used manufacturing process for making plastic products mainly due to its high efficiency and manufacturability. The design of injection molding systems relies heavily on material data and related information. The availability of right material information at right time is of utmost importance for the design, operation and maintenance of the injection molding process. In this paper, a concise, and conceptual Injection Molding Material Information Model (IM-MIM) is proposed to support necessary computer-based modeling, calculation and management of material data. In this paper, we study different steps of the IM process from the information-modeling viewpoint to identify the role and influence of material properties and behaviors in decision-making process. We further developed a four-level IM-MIM model framework, which provides a foundation for different material-related activities or analyses. Several key components in the IM-MIM, which consists of the material data, physical and behavioral properties, thermodynamic and transport properties, and other material information like rheological and mechanical properties, are presented in detail.

Commentary by Dr. Valentin Fuster
2014;():V004T06A059. doi:10.1115/DETC2014-35205.

This paper discusses the use of the proposed Material Information Model (MIM) [1] in assessing the sustainability of the Injection Molding (IM) process, and clarifies how to use the material information (based on the characteristics of different types of polymers) to quantify the material impacts. The assessment criteria include energy/water consumption and waste (pollution) production during the process and the effects of other materials during production (like the use of additives) that may add to environmental burdens. This paper addresses issues mainly at the IM process level taking the followings into account — pollution and manufacturing cost, energy and water consumption, waste management, operation safety, hazards to the plastic manufacturing personnel and other environmental impacts — to develop requisite process metrics for measuring the sustainability performances of the IM process. The ideas discussed in the paper lead to the development of computational approaches for selecting the “best” process-material combination.

Commentary by Dr. Valentin Fuster
2014;():V004T06A060. doi:10.1115/DETC2014-35642.

Sustainable design is a universal concern and due to that it becomes significant reference in numerous industries especially furniture products. In order to overcome the difficulties in Furniture Industry to determine the sustainable design to their products, the concept of Sustainable Design Index (SDI) was proposed in this paper. The SDI construction is combined with the designer’s daily activities and the design process, in this research the open plan system (OPS) is used for the subject matter. This paper presents several design tools and strategies which are integrated to support the development of sustainable design index as a solution. It is important to develop a model or method for formulating the SDI for industry to work with particularly the product’s sustainability performance strongly linking to the consumer’s satisfaction. In order to develop a robust SDI representation, an innovative approach for structured and systematic sustainable furniture design is proposed mainly based on modular product architecture, reconfigurability, using design structure matrix (DSM) and axiomatic design (AD). The SDI implementation is to enhance the designer by seamlessly integrating SDI algorithms within the CAD design environment and designers’ design operations.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Bio MEMS/NEMS

2014;():V004T09A001. doi:10.1115/DETC2014-34681.

Nonlinear forced vibration of fluid-conveying nanotubes based on Euler-Bernoulli beam theory under electromagnetic actuation is studied. The nanotube is modeled as cantilever type beam and the effects of fluid motion and external harmonic excitation are considered in the governing equation of the structure vibration. The Galerkin procedure is applied in order to discretize the governing equation of vibration of the system. The well-known multiple scales method is utilized to investigate the primary resonance in the forced vibration of nanotubes. The effects of various parameters, namely, fluid velocity, position of applied force, aspect ratio and electromagnetic excitation on the primary resonance of the system are fully investigated. It is revealed that the electromagnetic excitation is highly influential on the frequency response of the considered system.

Commentary by Dr. Valentin Fuster
2014;():V004T09A002. doi:10.1115/DETC2014-34705.

This paper discussed about the design and fabrication process of flexible MEMS based Differential Scanning Calorimeter that greatly enhanced the detection limit and accuracy that allowed for evaluation of molecular interaction. The design utilized polyimide to significantly reduce thermal conduction by hundreds of times than traditional used substrate material. Preliminary fabrication result had successfully demonstrated the polyimide membrane can be firmly adhesive on the wafer during fabrication and easily peeled off from the rigid substrate after the process. Temperature sensing material, VOx was prepared by DC magnetron sputter of sintered vanadium target with O2 flow during the sputtering. Deposition conditions such as the O2 flow rate’s influence on the electrical resistivity and temperature coefficient resistance was investigated. The results fully showed that the material prepared by the method has satisfactory performance to be used as thermistor in the calorimeter. Also, research about thermal analysis of the system further guided and confirmed the feasibility of the design.

Topics: Manufacturing , Design
Commentary by Dr. Valentin Fuster
2014;():V004T09A003. doi:10.1115/DETC2014-34843.

In this study, a novel and simple electrochemical glucose biosensor based on a silicon nanowire array (SNA) electrode was proposed. Metal-assisted etching (MAE) method using an AgNO3 and HF mixing solution as the etchant was employed to grow the silicon nanowire array (SNA) electrode. A thin gold shell is then sputtered over each silicon nanowire. Potassium ferricyanide, glucose oxidase (GOx), and a Nafion thin film were then sequentially coated onto the fabricated SNA for glucose detection. The processing time of the MAE and sputtering as well as the GOx concentration were optimized in terms of the redox peak currents of the SNA electrode. Compared with the corresponding plane gold electrode, the effective sensing area of the synthesized SNA electrode was measured to be 6.12 folds. Actual glucose detections demonstrated that the proposed SNA array electrode could operate in a linear range of 0.55 mM-11.02 mM and a very high sensitivity of 346 μA mM−1 cm−2. The proposed SNA electrode based glucose biosensor possesses advantages of simple fabrication process, low cost, and high sensitivity. It is feasible for future clinical applications.

Commentary by Dr. Valentin Fuster
2014;():V004T09A004. doi:10.1115/DETC2014-34866.

In this study, a PCR free technique for effective detection of hepatitis B virus (HBV) DNA obtained directly from clinical samples was presented. The honeycomb-like barrier layer of an anodic aluminum oxide (AAO) film having a uniform nanohemisphere array was used as the substrate of the sensing electrode. A gold thin film about 30 nm thick was radio-frequency (RF) magnetron sputtered onto the AAO barrier-layer surface as the electrode for the successive deposition of gold nanoparticles (GNPs) on the hemisphere surface. A specially designed single-strand 96-mer gene fragment of the target genomic DNA of HBV based on the genome sequences of HBV from the National Center for Biotechnology Information (NCBI) was immobilized on the nanostructured electrode as the capture probe. Complementary target HBV DNA (3020–3320 mer) obtained from clinical samples were further hybridized to the sensing probes. Detection results through electrochemical impedance spectroscopy (EIS) illustrate that two dynamic linear ranges, 0–103 and 103–105 copies/mL, having R2 values of 0.973 and 0.998, respectively, could be obtained. A detection limit of 186 copies/mL could be achieved. The proposed simple and high performance HBV DNA detection technique in this study is highly feasible for future clinical applications.

Topics: Biosensors , DNA
Commentary by Dr. Valentin Fuster
2014;():V004T09A005. doi:10.1115/DETC2014-35122.

An automated nanoinjection system has been developed and tested for the delivery of propidium iodide into culture cells. Nanoinjection is the process by which molecules are delivered into living cells using a solid needle. Propidium iodide, a dye that fluoresces when bound to nucleic acids, was used as the injection molecule to monitor nanoinjection efficiency. The nanoinjection system uses a programmable microcontroller to manipulate a linear actuator, which presses a silicon lance array into thousands of living culture cells simultaneously. The lances penetrate cell membranes, allowing dye molecules to enter the cell through membrane pores opened by lances. The system was developed to apply the same injection force to each cell sample at the press of a button, eliminating any experimental variability in data due to the operator. Tests were performed at a dye concentration of 0.04 mg/mL for all experiments. Several forces were tested to determine the optimal nanoinjection force needed for maximum dye delivery. We found the optimal force range to be 8.8–14.7 N. The average PI uptake into cells at a force of 8.8 N and 14.7 N is 57.6±7.7% and 60.3±6.6%, respectively. Previous studies with a manual injection force have shown average propidium iodide uptake to be 60.4±18.0%. High cell viability is maintained with the automated nanoinjection system. At all forces applied in this experiment, an average of 78% or greater viability was observed. With the data gathered in this experiment, we conclude that the automated nanoinjection system eliminates much of the uptake efficiency variability inherent to nanoinjections performed with a manual injection force.

Commentary by Dr. Valentin Fuster
2014;():V004T09A006. doi:10.1115/DETC2014-35431.

Being able to deliver molecular loads to the intracellular space of mammalian cells is a key initial step of genetic engineering. In the following work, experimentation with nanoinjection, a non-viral molecular load delivery technique, was examined in regards to transmembrane delivery of propidium iodide (PI), a dye that cannot penetrate the cell membrane and fluoresces when bound to genetic material. Investigation includes two environmental factors: peak pulse amplitude (1.5 to 3, 5, 7, or 9 V) and saline type (HBSS, PBS with potassium, and PBS without potassium). Results indicate that PBS with potassium has significantly higher PI uptake efficiency than the other two saline solutions for pulsed voltages of 3V, 5V, and 7V (with the peak value being 3.352 times greater than the positive control). Also, cell viability analysis indicates that there is a measureable reduction in cell viability for voltage protocol samples in comparison to non-voltage protocol samples. Cell viabilities range from 74.5% to 89.4% for voltage protocol samples. Findings suggest that a possible combination of physical/electrical variables work in concert with biological mechanisms to contribute to overall cell survival and PI uptake efficiency in nanoinjection.

Commentary by Dr. Valentin Fuster
2014;():V004T09A007. doi:10.1115/DETC2014-35496.

This investigation deals with M/NEMS circular plates under electrostatic actuation. Such structures can be used as resonator sensors for medicine and biology applications such as virus, bacteria or DNA detection. The system consists of a clamped circular plate over a ground. The actuation of the plate is done through an AC voltage whose frequency is near half natural frequency of the plate. This produces a primary resonance to be used afterwards for sensing purposes. It is showed that a saddle-node bifurcation occurs. The effects of damping, voltage, Casimir, and van der Waals forces are predicted.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Dynamics of MEMS and NEMS

2014;():V004T09A008. doi:10.1115/DETC2014-34880.

Micro and nano devices incorporating bi-stable structural elements such as micro beams are designed to exploit the fact that the latter possess two stable configurations at the same actuation force. Generally, the transition of a micro beam from one table state to another, namely the snap-through which is essentially dynamic phenomenon, can be initiated by either static or dynamic activations. In this work, results of theoretical and numerical investigations of the transient dynamics of a pre-stressed initially curved double clamped micro beams actuated by a time dependent electrostatic load are presented. We show by means of a reduced order model of a shallow beam, derived using the Galerkin procedure, that the beam may exhibit various types of responses. For certain beam characteristics, the second stable state is inaccessible under a static loading but is attainable only by means of a specially tailored dynamic actuation. This gives way to the possibility of trapping the dynamically bi-stable beam at a stable configuration which is close to the electrode by applying special loading sequences.

Topics: Microbeams
Commentary by Dr. Valentin Fuster
2014;():V004T09A009. doi:10.1115/DETC2014-34904.

We investigate the collective nonlinear behavior of an array of micro cantilevers interacting by fringing electrostatic fields and fabricated of silicon on insulator (SOI) wafer. The interaction is due to the mechanical coupling originated in the flexibility of the anchor and of the electrostatic coupling through voltage-dependent electrostatic force. In the framework of the reduced order model based on the Galerkin decomposition the array is considered as an assembly of single degree of freedom oscillators. The mechanical coupling matrix is extracted using the full scale finite element analysis of the array while the electrostatic force is approximated by a fit build using the three-dimensional numerical simulation. We show numerically and experimentally that large amplitude collective vibrations of the array can be achieved using parametric excitation while the dynamic properties of the array can be efficiently tuned by the applied voltage.

Commentary by Dr. Valentin Fuster
2014;():V004T09A010. doi:10.1115/DETC2014-34917.

We study the static and dynamic behavior of electrically actuated micromachined arches. First, we conduct experiments on micromachined polysilicon beams by driving them electrically and varying their amplitude and frequency of voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Next, we conduct analytical and theoretical investigation to understand the experiments. First, we solve the Eigen value problem analytically. We study the effect of the initial rise on the natural frequency and mode shapes, and use a Galerkin-based procedure to derive a reduced order model, which is then used to solve both the static and dynamic responses.

We use two symmetric modes in the reduced order model to have accurate and converged results. We use long time integration to solve the nonlinear ordinary differential equations, and then modify our model using effective length to match experimental results.

To further improve the matching with the experimental data, we curve-fit the exact profile of the microbeam to match the experimentally measured profile and use it in the reduced-order model to generate frequency-response curves.

Finally, we use another numerical technique, the shooting technique, to solve the nonlinear ordinary differential equations. By using shooting and the curve fitted function, we found that we get good agreement with the experimental data.

Commentary by Dr. Valentin Fuster
2014;():V004T09A011. doi:10.1115/DETC2014-34918.

We present analytical solutions of the electrostatically actuated initially deformed cantilever beam problem. We use a continuous Euler-Bernoulli beam model combined with a single-mode Galerkin approximation. We derive simple analytical expressions for two commonly observed deformed beams configurations: the curled and tilted configurations. The derived analytical formulas are validated by comparing their results to experimental data in the literature and numerical results of a multi-mode reduced order model. The derived expressions do not involve any complicated integrals or complex terms and can be conveniently used by designers for quick, yet accurate, estimations. The formulas are found to yield accurate results for most commonly encountered microbeams of initial tip deflections of few microns. For largely deformed beams, we found that these formulas yield less accurate results due to the limitations of the single-mode approximations they are based on. In such cases, multi-mode reduced order models need to be utilized.

Commentary by Dr. Valentin Fuster
2014;():V004T09A012. doi:10.1115/DETC2014-34949.

Frequency stability is a desirable property for micro- and nanoelectromechanical system oscillators used in reference and timing applications. In case of doubly-clamped oscillators, resonant frequencies are highly sensitive to the operating temperature because of development of internal stresses due to thermal expansion under the restraint of fixed boundary conditions. In this paper, we present a design procedure to reduce the variation of resonant frequency with respect to change in operating temperature, in other words improve the frequency stability, by exploiting the interaction between electrostatic and geometric nonlinearities in electrostatically actuated doubly-clamped nano-oscillators. We have modeled the nano-oscillators using Euler-Bernoulli beam theory and Galerkin based reduced order modeling technique. We have examined first natural frequency variation due to temperature change for different carbon nanotube oscillators and an optimization based design procedure has been devised for improving the frequency stability.

Commentary by Dr. Valentin Fuster
2014;():V004T09A013. doi:10.1115/DETC2014-35626.

Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction of their cylindrical shape, forming upper electrodes, to lower electrodes poises serious computational challenges. This presents an obstacle against applying and using several nonlinear dynamics tools that typically used to analyze the behavior of complicated nonlinear systems, such as shooting, continuation, and integrity analysis techniques. This works presents an attempt to resolve this issue. We present an investigation of the nonlinear dynamics of carbon nanotubes when actuated by large electrostatic forces. We study expanding the complicated form of the electrostatic force into enough number of terms of the Taylor series. We plot and compare the expanded form of the electrostatic force to the exact form and found that at least twenty terms are needed to capture accurately the strong nonlinear form of the force over the full range of motion. Then, we utilize this form along with an Euler–Bernoulli beam model to study the static and dynamic behavior of CNTs. The geometric nonlinearity and the nonlinear electrostatic force are considered. An efficient reduced-order model (ROM) based on the Galerkin method is developed and utilized to simulate the static and dynamic responses of the CNTs. We found that the use of the new expanded form of the electrostatic force enables avoiding the cumbersome evaluation of the spatial integrals involving the electrostatic force during the modal projection procedure in the Galerkin method, which needs to be done at every time step. Hence, the new method proves to be much more efficient computationally.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: MEMS for Aeronautical and Space Applications

2014;():V004T09A014. doi:10.1115/DETC2014-35570.

Micro and nano technology has demonstrated the capability of creating miniaturized systems leading to significantly reduced mass, volume or power requirements, and therefore reduced cost but more advanced performances. Such micro systems are critical in the development of future space systems such as picosatellites, planetary probes, on-board instruments or nanorovers and swarm micro robotics. A pneumatically driven micro device has been proposed for manipulating and assembling space components or building-up a larger scale system based on individually launched micro robots. The device is a four fingered microhand actuator made of silicon rubber to grasp micro objects utilizing air pressure inside of its internal cavities. The grasp force and tip displacement of the fingers has been simulated using FEM. A prototype has been fabricated to validate its performance and the three-dimensional motion control using piezoelectric sensors to monitor the deflection in the fingers of the device.

Topics: Actuators , Robotics
Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: MEMS Sensors and Actuators

2014;():V004T09A015. doi:10.1115/DETC2014-34283.

An electrostatic actuator is designed to move a 1 mm mirror, 58 μm out of plane at 25 volts. Large out-of-plane displacement is obtained from repulsive forces generated on four sets of comb drive fingers attached to the mirror plate in the middle. The proposed actuator is a customized design of a previous study for low voltage applications. The static modeling of the actuator was performed using a coupled-field finite element model of the actuator, including mechanical and electrical domains. Low voltage operation is achieved by decreasing the finger width and the lateral spacing, which increased the generated repulsive force at a specified voltage in a unit cell of the actuator. Decreasing the lateral spacing also enabled increasing the number of fingers, which could increase the repulsive-force, and consequently the torque and the rotation angles when the vertical gap between moving and fixed fingers is small. However, the redesigned actuator has a lower stiffness compared to the previous design. The actuator is optimized for auto-focusing applications in cell phone cameras that require voltages below 30 Volts for user safety. In the intended auto-focusing module, the actuators do not carry the lens and auto-focusing is obtained by moving the mirror attached to the actuators.

Commentary by Dr. Valentin Fuster
2014;():V004T09A016. doi:10.1115/DETC2014-35004.

This paper introduces a novel MEMS magnetic field sensor based on the Lorentz force. It measures torsional vibrations excited via Lorentz force. The sensor sensitivity and dynamic range can be tuned by varying an electrostatic bias. Experimental demonstration shows that the sensor sensitivity can be changed from 0.7 (m/s)/T at 6 V DC bias to 1.4 (m/s)/T at 0 V DC bias.

Commentary by Dr. Valentin Fuster
2014;():V004T09A017. doi:10.1115/DETC2014-35104.

Transparent organic solar cells have recently attracted extensive interest considering their potential application for the power-generating window. By allowing the transmission of visible light while converting ultraviolet and near infrared light in the solar spectrum into electricity, transparent solar cells integrated into building facade provide a smart solution to the energy dilemma in urban area. However, current works mainly optimize the performance of solar cells for very limited incident condition, such as only considering normal incidence, which results in impractical designs for real applications. In this paper, we propose a robust design approach to achieve high-performance transparent solar cell based on a non-periodic photonic structure considering a broad range of incident conditions representing natural sunlight illumination. Statistical performances are used in the robust design formulation and efficient sampling techniques are further employed to improve the computational efficiency. The Pareto-optimal solutions are obtained according to the multicriteria preference with respect to maximizing the expected cell transparency and the expected energy conversion efficiency, and minimizing the performance variance due to the incidence variation. As one example of the optimized design, the absorbing efficiency of the solar cell could be up to 85% that of its opaque counterpart with 32% visible light transmission and 0.13% variation coefficient of transparency under the actual solar illumination and incident angles from 9am to 3pm. By using this design methodology, practically efficient cell structure is achieved based on the location and installation orientation of the solar window.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Micro and Nanomanufacturing

2014;():V004T09A018. doi:10.1115/DETC2014-34258.

Nano particle deposition system (NPDS) had been developed for the creation of micro/nano structures with multimaterials in order to develop the micro/nano devices on the basis of specific localized surface on the multilayer. However, micro structures fabricated by NPDS show different mechanical properties when it compared to bulk material because of its porous and uneven deposition structure. To achieve reasonable mechanical properties of the structure fabricated by nanoscale 3D printing system, it requires in-situ mechanical property test method. Herein, a new approach for in-situ nanomechanical characterization system using microforce sensor and nanomanipulator installed in focused ion beam system. In this research, experimental setup for mechanical characterization was developed and mechanical property test was done in Focused Ion Beam (FIB) system. The specimen was fabricated by FIB milling process, then manipulation and compression processes are operated by this characterization system with real time imaging. The test was done for silver microstructures fabricated by NPDS and results show weaker hardness and smaller young’s modulus than bulk material.

Commentary by Dr. Valentin Fuster
2014;():V004T09A019. doi:10.1115/DETC2014-34373.

In this paper, the pulse discrimination of gap voltage and discharge current waveforms occurring during micro-EDM milling of micro-channels is analyzed in relation to process parameters variation and machining performance. The pulse classification algorithm discriminates voltage and current waveforms into four defined pulse types: short, arc, delayed and normal. The micro-channels are manufactured in hardened steel using an energy level corresponding to the finishing regime and varying pulse width, frequency, gain and gap. The analysis shows that when the erosion process is stable, normal discharges are predominant. Delayed and short pulses are very sporadic. A major number of arcs can be detected when the gap is decreased and gain increased, i.e. erosion speed and feed rate are increased and affect in particular tool wear. Also the increase of the pulse width has an effect on tool wear, though the percentage of the arcs remains small. On the contrary, material removal rate does not seem to be apparently related to the percentage of arcs as the process parameters are varied, since these values are spread in a constant range for all parameter combinations. The evaluation of the depth errors does not provide any significant insights about the erosion process in relation to the considered process parameters.

Commentary by Dr. Valentin Fuster
2014;():V004T09A020. doi:10.1115/DETC2014-35083.

Nowadays, the study of polymer nanocomposites is an active area of materials development because nanofillers and in particular Multi-Wall Carbon Nanotubes (MWCNTs) can significantly improve or adjust the properties of the materials into which they were incorporated such as optical, electrical, mechanical and thermal properties. MWCNTs have been adopted in quite a number of applications, but advancements in their properties are needed for spreading their potential. Moreover their behaviour and filling properties in micro injection moulding process have still to be studied.

Therefore, in this work, experimental and statistical studies were performed to analyze the parameters effect on replicating capability of micro parts manufactured in POM/MWCNT by micro injection moulding process. Two compounds with different filler fraction (3 and 6 wt%) were tested and processed with different conditions and their operating range have been pointed out and compared with that of pristine POM (PolyOxyMethilene).

The results show that the filler content has the effect to change slightly the operative range of the micro injection process parameters and to increase the replicating capability. The most effective parameters on replicating capability of micro ribs, evaluated by a dimensional index, are the mould temperature for the POM/MWCNT 3% and injection velocity for the 6% filler fraction.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Micro and Nanomechanisms and Robotics

2014;():V004T09A021. doi:10.1115/DETC2014-35145.

A fabrication procedure is presented for creating microactuation elements that link piezoelectric thin-films with high-aspect ratio parylene microstructures. Resulting actuators permit relatively large rotational motions for low voltage operation, while maintaining large weight-bearing capacity. Actuator fabrication is performed on a silicon wafer though a combination of metal and thin-film lead-zirconate-titanate (PZT) deposition and patterning, parylene refill of high-aspect ratio trenches, and dry release of moving parts from the silicon substrate. Static and dynamic responses of various test structures are measured, to estimate material properties of the integrated PZT-polymer structures, for use in future actuator modeling and optimization.

Commentary by Dr. Valentin Fuster
2014;():V004T09A022. doi:10.1115/DETC2014-35162.

In precise manipulation and assembly of components with sub-millimetric dimensions, the role of the gripping tools is fundamental. In the literature, many different types of the so-called microgrippers have been presented, based on different working principles, to cope with the issues related to the gripping, the handling and the release of different micro-components. Depending on the component properties, the task requirements and the system constraints, a microgripper could be more suitable than another and allow the achievement of higher performance. However, the performance assessment of the microgrippers lacks of a standardized and quantitative methodology. Many authors declare the good capabilities of their tools in a qualitative way or according to the results obtained executing specific and different tasks. For this reason, it is often difficult to compare different microgrippers and estimate the actual results that can be obtained e.g. in the gripping or the release of a component. In this context, after a preliminary survey of the adopted approaches in literature and of their meaning, this paper investigates the conception and formalization of methods and procedures to evaluate the performance of a generic microgripper and the definition of standard performance indices to support the presentation of the microgripper characteristics.

Commentary by Dr. Valentin Fuster
2014;():V004T09A023. doi:10.1115/DETC2014-35504.

Nano Magnetic Particles drug delivery is a new method of cancer treatment targeting the replacement of current methods such as chemotherapy and radiation to increase the efficiency of treatment. This project aims to design a system including experimental setup and computational platforms that will work parallel to each other developing guidelines for scientists. The Computational platform is able to model the nano particle’s aggregations and movement. Experimental setup will be used to generate results validating the simulations done on the computational platform. Experimental setup has the potential to operate Magnetic nanoparticles drug delivery in different scale and situations. We aim to make the experimental setup as close as possible to human blood properties. This will enable us to come up with guiding trajectories and control algorithms for guidance of different size and shape nano particles in arbitrary capillary shapes. This data can be beneficial for researchers doing experiments on magnetic drug delivery and avoid the In vivo experiments for the sake of animal rights. We present software called MAGNASIM that is being developed to perform simulation, visualization and post-processing analysis of the aggregation and disaggregation processes of magnetic Nano/Micro particles within a fluid environment such as small arteries and arterioles or fluid-filled cavities of the human body. Basically the software would be able:

• To examine Self-assembly process and breakup process

• To provide design guidelines for fabricating, control and steering the nanocapsules

After gathering all the initial conditions, software is able to provide the user the following information:

• Forces on each particle in each time-step.

• Position of each particle in each time-step.

• Interactions between particles.

• Control and steer the particles to the considered destination.

• Providing visualization of the particles movement.

Commentary by Dr. Valentin Fuster
2014;():V004T09A024. doi:10.1115/DETC2014-35649.

This paper investigates the actuation of untethered microrobots with a focused magnetic field generated by a permanent magnet wand. The microrobots are chrome-steel spheres or Neodynium cubes with a size of 250 μm, which perform desired planar motions directed by the movement of the wand. We propose and evaluate novel methods to enhance the focused magnetic field of the wand by sharpening its tip, increase microrobot velocities via novel mechanical amplifiers, and reduce environmental forces via inexpensive anti-friction coatings. We document results of automated operation and teleoperated control of the microrobot during competition at the Mobile Microrobotics Challenge (MMC) held in 2013. Experimental results from the mobility and microassembly challenge indicate an excellent degree of precision motion control over the robot, at a price of a slightly lower maximum speed when compared to conventional electromagnetic actuation.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Micro Mechanics and Surface Engineering of Artificial and Biological Materials

2014;():V004T09A025. doi:10.1115/DETC2014-34857.

Silicon nitride films were attracting extensive research interest in the past few decades as hard disk protective coating, especially the beta-silicon nitride (β-Si3N4) films and amorphous silicon nitride (SiNx) films, which have high hardness, chemical durability and low friction coefficient properties against wear, corrosion and reducing the friction resistance, respectively. Considerable efforts have been made in studying silicon nitride. However, it’s difficult to determine its nano-tribological properties experimentally since the results were affected by a lot of contact and environment conditions.

The molecular dynamics (MD) simulation method is employed in this work. A rigid diamond sphere modeled as a spherical tip are sliding over a layered silicon nitride film substrate, respectively, to investigate the tribological properties of silicon nitride films. The effect of the relative sliding velocity and sliding direction, the normal force and the thickness of crystalline silicon nitride films on the friction coefficient of silicon nitride films were investigated.

Commentary by Dr. Valentin Fuster
2014;():V004T09A026. doi:10.1115/DETC2014-35110.

This paper proposes a hybrid (semi-analytic) solution for determining the contact footprint and subsurface stress field in a two-dimensional adhesive problem involving a multi-layered elastic solid loaded normally by a rigid indenter. The subsurface stress field is determined using a semi-analytic solution and the footprint using a fast converging iterative algorithm. The solid to be indented consists of a graded elasticity coating with exponential increase of decay of its shear modulus bonded on a homogeneously elastic substrate. By applying the Fourier Transform to the governing boundary value problem, we formulate expressions for the stresses and displacements induced by the application of line forces acting both normally and tangentially at the origin. The superposition principle is then used to generalize these expressions to the case of distributed normal pressure acting on the solid surface. A pair of coupled integral equations are further derived for the parabolic stamp problem which are easily solved using collocation methods.

Commentary by Dr. Valentin Fuster
2014;():V004T09A027. doi:10.1115/DETC2014-35276.

Recent advances in polymer technology together with the growing need of smaller and lighter electronic components and biomedical equipment led to the development of new applications of polymers at micro scale. However, unlike traditional materials (e.g., metal silicon), polymers exhibit a significant time dependency in their response to load (e.g., viscoelastic, hyperelastic). Therefore, predicting the behavior of such polymer components at small scale requires accurate simulations of the effects of creep and relaxation within the systems. The current study uses a mesh-free particle method (smoothed particle hydrodynamics) to predict time-dependent mechanical response of polymers. As a first step towards investigating the response of a polymer microstructure under load, we simulate the behavior of a slender polymer rod compressed and tangentially dragged against a smooth glass surface.

It is shown that although accurate prediction of polymer deformation cannot be achieved with a fully analytic model, a simplified generalized Kelvin model could calibrated to capture most of the characteristics of the fully numerical model. This cold be used for predicting the behavior under load of a passive subsystem of imbedded in a control algorithm to extend the measuring domain of a possible sensor or prevent potentially dangerous operating conditions.

Commentary by Dr. Valentin Fuster
2014;():V004T09A028. doi:10.1115/DETC2014-35580.

Companies that coat their products with DLC often have strict surface roughness goals. This research investigates the surface roughness properties of uncoated and DLC coated specimens in an effort to know what uncoated surface roughness is needed to obtain a certain DLC coated surface roughness. Therefore, a model describing the relationship between uncoated and DLC coated surface roughness is needed. If this relationship can be estimated, the cost of surface finishing can be minimized by avoiding any unnecessary processes. A total of 7 specimens were tested before and after coating process with a non-contact surface roughness measurement microscope. Mathematical relationships are found between the DLC coated surface roughness and uncoated surface roughness. An experimental methodology was described for applying the findings to other coating methods and materials as the mathematical relationships found in this study are specific to the coating process and materials used.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Microscale Energy Harvesting

2014;():V004T09A029. doi:10.1115/DETC2014-34823.

The excellent combination of high strength, stiffness, low density and aspect ratio makes carbon nanotubes ideal reinforcement for nanocomposites. The load transfer between the outer and inner layers of multiwalled carbon nanotubes (MWCNT) is one of the important factor in the reinforcement of nanocomposites. In this work, the effect of variation in number of layers of multiwalled carbon nanotubes on effective tensile, compressive and transverse modulus of composite is evaluated. A 3-D finite element model based on representative volume element, consisting of multiwalled carbon nanotube made of shell elements surrounded by solid matrix material is built. With the increase in number of layers in multiwalled carbon nanotubes, the compressive modulus of composite increases, while the tensile modulus decreases. The transverse modulus of composite is found to increase, with the increase in number of layers in MWCNT. The finite element results for composite are compared with the rule of mixtures results using formulae.

Commentary by Dr. Valentin Fuster
2014;():V004T09A030. doi:10.1115/DETC2014-35093.

We investigate a new type of nonlinear vibration energy harvester that uses a double impact oscillator as its harvesting element. A prototype of the harvester is analyzed numerically and experimentally when aligned vertically. Results show that the new architecture enhanced the output power as well as the frequency bandwidth in comparison with linear harvesters. The new harvester is capable of generating up to 250 mV and has a harvesting bandwidth of about 6 Hz. The optimal load for 0.7 g input acceleration is found to be 5.5 Ω and the corresponding optimal power is determined to be 8 mWatts.

Commentary by Dr. Valentin Fuster
2014;():V004T09A031. doi:10.1115/DETC2014-35417.

In this paper, a piezoelectric leaf generator for harvesting wind energy was proposed, fabricated and tested. The leaf generator had a bimorph cantilever structure, with Su-8 as the protective supporting layer, and aligned lead zirconate titanate (PZT) nanofibers as the active layer. Interdigitated electrodes were sputtered on top of the aligned PZT nanofibers to collect the generated charge. After fabrication of the leaf generator, it was tested in a wind tunnel with different wind incident angles and wind speeds. The maximum voltage output of the leaf generator was 820 mV when the wind speed was 17 m/s. The developed leaf generator does not need further bonding to the vibration source, which make it much easier for real applications. In addition, benefited from unique material properties of the PZT nanofiber such as flexible, robust, and high piezoelectric coupling ability, the leaf generator is promising for a high efficiency wind energy harvest.

Commentary by Dr. Valentin Fuster

8th International Conference on Micro- and Nanosystems: Nonlinear Mechanics, Dynamics, and Control in Atomic Force Microscopy

2014;():V004T09A032. doi:10.1115/DETC2014-35479.

Many types of nonlinear phenomena have been studied in atomic force microscopy (AFM). As a tool for performing topographical measurements and material characterizations at the micro- and nano-scales, improving the understanding of the dynamic AFM system will impact many areas of research. The authors’ previous studies have shown that in dynamic AFM, with dual-frequency excitation, influence of attractive and repulsive interaction forces can be revealed by the presence of specific frequency components in the response. Motivated by the phenomenon predicted in the AFM system, a macro-scale test platform is used in this effort in order to qualitatively investigate the relationships between the dual-frequency excitation, interaction conditions, and the specific frequency components observed in the response. The experimental setup includes a base driven cantilever with a tip, a soft material as the sample and an electromagnet behind the sample to provide attractive interaction forces. The components in the experimental setup are characterized and the system is studied by using numerical and experimental methods. A thorough numerical and experimental study of the influence of the phase difference between the two frequency components in the excitation signal is investigated in this work.

Commentary by Dr. Valentin Fuster
2014;():V004T09A033. doi:10.1115/DETC2014-35673.

Quartz tuning fork (QTF) sensors offer an attractive alternative to traditional silicon microcantilevers for sensing applications in dynamic atomic force microscopy (DAFM). The QTF sensor consists of two identical, weakly-coupled tines with a sharp tip affixed to the distal end of one tine. The fundamental anti-phase mode of the QTF achieves a stable resonant frequency with a high Quality factor making it ideal for DAFM applications in which a small shift in the resonant frequency is linked to a tip-sample force. The addition of the tip-sample force also breaks the symmetry of the QTF leading to a classic eigenvalue veering scenario. The eigenvalue veering and accompanying mode localization phenomena violate the standard DAFM modeling assumptions which treat the addition of the tip-sample force as a small perturbation to a single-degree-of-freedom oscillator. We find that the eigenvalue veering can contribute a systematic error in force measurements on the order of 20%. Methodology for correcting the systematic error caused by eigenvalue veering is proposed.

Commentary by Dr. Valentin Fuster

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