bluuebunny/crossref_metadata_2025 huggingface dataset:
Merge-Based Design: A New Method for Managing Variety and Improving Customization
Authors: Alizon Fabrice , Williams Callida , Shooter Steven B. , Simpson Timothy W.
Published: May 2009

With markets becoming more and more fragmented, the management of product variety becomes even more critical. Variety management needs to be continuously improved, especially for highly customized products. Although new techniques are constantly being developed, variety is still an issue, and there is room for complementary assistance to manage variety in the final design. In this context, we propose an original method — merge-based design — to manage variety in a product family better. The proposed method targets the already-tailored (unique) components to reduce the number of variant components in the family. Merge-based design also facilitates customization by enabling designers to reduce non-beneficial variety within a family. The proposed method is described and then illustrated via a case study involving two existing internal structures from single-use cameras. Finally, to highlight for improving customization, a proposed new camera is created using the resulting common structure with a different exterior casing. This new method can be applied during detailed studies as well as in the early stages of the design process.
An Adaptive Observer for Sideslip Angle Estimation: Comparison With Experimental Results
Authors: Cheli Federico , Melzi Stefano , Sabbioni Edoardo
Published: May 2009

By observing the lateral vehicle dynamics and in particular the sideslip angle, the detection of critical driving situations is possible. Thus, an adaptive observer for sideslip angle estimation is proposed in this paper. According to the proposed methodology, the sideslip angle is estimated as a weighted mean of the results provided by a kinematic formula and the ones obtained using a state observer based on a linear single-track vehicle model; tires cornering stiffness are updated during the transitory phase of a maneuver in order to take into account nonlinearities and changing of adherence conditions between tires and road.
A Polynomial-Chaos-Based Bayesian Approach for Estimating Uncertain Parameters of Mechanical Systems
Authors: Blanchard Emmanuel , Sandu Corina , Sandu Adrian
Published: May 2009

In this study, a new computational approach for parameter identification is proposed based on the application of the polynomial chaos theory. The polynomial chaos method has been shown to be considerably more efficient than Monte Carlo in the simulation of systems with a small number of uncertain parameters. In the new approach presented in this paper, the maximum likelihood estimates are obtained by minimizing a cost function derived from the Bayesian theorem. Direct stochastic collocation is used as a less computationally expensive alternative to the traditional Galerkin approach to propagate the uncertainties through the system in the polynomial chaos framework. The new parameter estimation method is illustrated on a four degree-of-freedom roll plane model of a vehicle in which the vertical stiffnesses of the tires are estimated from periodic observations of the displacements and velocities across the suspensions. The results obtained with this approach are close to the actual values of the parameters even when only measurements with low sampling rates are available. The accuracy of the estimations has been shown to be sensitive to the number of terms used in the polynomial expressions and to the number of collocation points, and thus it may become computationally expensive when a very high accuracy of the results is desired. However, the noise level in the measurements affects the accuracy of the estimations as well. Therefore, it is usually not necessary to use a large number of terms in the polynomial expressions and a very large number of collocation points since the addition of extra precision eventually affects the results less than the effect of the measurement noise. Possible applications of this theory to the field of vehicle dynamics simulations include the estimation of mass, inertia properties, as well as other parameters of interest.
A Novel Wheel-Soil Interaction Model for Off-Road Vehicle Dynamics Simulation
Authors: Chan Brendan J. , Sandu Corina
Published: May 2009

This work establishes a semi-empirical wheel-soil interaction model, developed in the framework of plasticity theory and equilibrium analysis, to be used in vehicle dynamics simulations. Vehicle-terrain interaction is a complex phenomena governed by soil mechanical behavior and tire deformation. The application of soil load bearing capacity theory is used in this study to determine the tangential and radial stresses on the soil-wheel interface. Using semi-empirical data, the tire deformation geometry is determined to establish the drawbar pull, tractive force, and wheel load. To illustrate the theory developed, two important case studies are presented: a rigid wheel and a flexible tire on deformable terrain; the differences between the two implementations are discussed. The outcome of this work shows promising results which indicate that the modeling methodology presented could form the basis of a three-dimensional off-road tire model. In an off-road three-dimensional tire model, the traction behavior should include shear forces arising from the surface shear with the soil as well as the bulldozing effect during turning maneuvers.
Comparison of Static and Dynamic Models for the Force Output of Magnetorheological Dampers
Authors: Richards Russell J. , Sandu Corina , Southward Steve C.
Published: May 2009

Magnetorheolgical (MR) fluid dampers have the capability of changing their effective damping force depending on the current input to the damper. A number of factors in the construction of the damper, as well as the properties of the fluid and the electromagnet, create a dynamic response of the damper that cannot be fully described with a static model dependant on current and velocity. In this paper, a static deterministic model for the force response of a damper will be compared to a time dependant dynamic model. Data collection was performed by providing a normally distributed random signal for velocity and a uniformly distributed random signal for current to Lord rheonetic seat damper; the signal distributions were chosen so dynamic effects were not artificially reduced. The parameters for the static and dynamic models were found by minimizing the error in force output. The error of the models is then compared, as well as the probability distribution for both models and the original data.
Laser-Assisted and Roller-Based Nano-Imprinting Technologies and Their Applications
Authors: Lee Yung-Chun , Chiu Cheng-Yu , Chen Chun-Hung , Chen Chun-Shiang
Published: May 2009

Nano-imprinting lithography (NIL) has been developed over 15 years and has shown its great potentials for nanopatterning and nano-fabrication. In this paper, new ideas on improving current nano-imprinting methods have been proposed and preliminary experimental tests are carried out. These proposed nano-imprinting methods are all based on the utilization of pulsed laser sources, either in UV or IR region, and can be easily implemented into a roller-based configuration, which is more effective and much faster than conventional planar type nano-imprinting methods. First of all, based on the Laser Assisted Direct Imprinting (LADI) method proposed in 2002, a modified roller-based LADI method is developed by applying a cylindrical quartz roller for mechanically loading as well as for optically focusing of a deep UV laser beam into a line. This modification not only fulfills a continuous type of LADI process but also more efficiently utilizes the laser energy so that large-area LADI is possible. Experimental testing demonstrates an imprinting rate of 3∼10 cm2/min. Secondly, a new nano-imprinting lithography based on pulsed infrared laser heating is proposed and demonstrated. It utilizes the partial transparency of silicon crystals at IR spectrum to heat up the photo-resist layer. Possible improvements and applications on this IR-NIL will be addressed. Finally, a new method of direct contact printing and patterning of a thin metal film on silicon substrate based on the idea of nano-imprinting is presented. This method combines the effects of loaded contact pressure and IR pulsed laser heating at the metal-film/substrate interface to form a stronger bonding between them, and therefore complete the direct pattern transferring of metal film on substrate. Good experimental results are observed and possible applications will be discussed.
Change Propagation Analysis in Complex Technical Systems
Authors: Giffin Monica , de Weck Olivier , Bounova Gergana , Keller Rene , Eckert Claudia , Clarkson John
Published: May 2009

Understanding how and why changes propagate during engineering design is critical because most products and systems emerge from predecessors and not through clean sheet design. This paper applies change propagation analysis methods and extends prior reasoning through examination of a large data set from industry including 41,500 change requests, spanning 8 years during the design of a complex sensor system. Different methods are used to analyze the data and the results are compared to each other and evaluated in the context of previous findings. In particular the networks of connected parent, child and sibling changes are resolved over time and mapped to 46 subsystem areas. A normalized change propagation index (CPI) is then developed, showing the relative strength of each area on the absorber-multiplier spectrum between −1 and +1. Multipliers send out more changes than they receive and are good candidates for more focused change management. Another interesting finding is the quantitative confirmation of the “ripple” change pattern. Unlike the earlier prediction, however, it was found that the peak of cyclical change activity occurred late in the program driven by systems integration and functional testing. Patterns emerged from the data and offer clear implications for technical change management approaches in system design.
Design and Technology of a Magnetic Levitation System for Linear Micro Actuators
Authors: Ruffert Christine , Gatzen Hans H.
Published: May 2009

A major drawback of magnetic linear micro actuators is the vertical attractive force between stator and traveler. In the case of a micro step motor, this force is typically one order of magnitude greater than the driving force itself. To compensate for this undesired vertical force and thus taking full advantage of the driving force available, a magnetic levitation system was developed and implemented as a guide. The electromagnetic field generated by the stator coils interacts with the field of permanent magnets positioned in the traveler. This way, the traveler is elevated. Since repulsive magnetic levitation systems are inherently unstable, a tribological guide was integrated on both sides of the magnetic levitation system. During motion, the combination of stationary coils in the stator and moving permanent magnets in the traveler lifts up the traveler, while the lateral tribological guide prevents the traveler from shifting sideways. Initial investigations proved the feasibility of this magnetic levitation concept (1). A complete linear micro step motor system with magnetic levitation guide consists of the micro step motor itself, the magnetic micro levitation system (including the lateral guides), and a capacitive air gap measurement system. The latter one detects the size of the air gap between stator and traveler of the micro actuator. An assembly consisting of the three components results in a linear micro actuator system with adjustable air gap. For achieving optimal working conditions of the linear micro step motor, the magnetic levitation system was designed for a nominal air gap of 8 μm at the micro step motor. While earlier work proved the feasibility of such a guide, it also indicated (i) that the levitation system has to be capable of correcting a pitch motion of the traveler and (ii) that an as high magnetic levitation force as possible is desirable. To address the first issue, the magnetic levitation system received four coils arranged in a square along the axis of motion of the micro step motor. This way, both pitch and roll may be controlled. For resolving the second issue, the number of coil layers was increased from two to four. The technology for such a four layer coil is quite challenging, particularly since every effort has to be made to minimize its building height. The challenges were resolved by creating a coil system where the lateral insulation between conductors consists of SU-8™ (a photosensitive epoxy by Micro Resist Technology), while the vertical insulation layers were formed by a thin, stress compensated Si3N4 film. This way, a very compact coil with a high conductor-to-insulator ratio and thus a great current conducting capability could be realized. Due to the thin Si3N4 insulation, it also features an excellent thermal conductivity.
Linear Synchronous Micro Motor With Further Miniaturized Dimensions
Authors: Bedenbecker Matthias , Hahn Matthias , Ruffert Christine , Gatzen Hans H.
Published: May 2009

When developing linear micro motors, the synchronous drive scheme is well suited since it offers relatively high driving forces while keeping the design, fabrication, and assembly relatively simple. After the feasibility of the application of the synchronous drive scheme in a micro motor was proven, a smaller version of the motor was developed to investigate this drive scheme’s miniaturization potential. Apart from scaling down the motor dimensions, further optimizations were applied using the results of FEM simulations. The micro motor was fabricated, assembled, and successfully tested. The results demonstrate that the synchronous linear micro motor was successfully scaled down. Furthermore, the results indicate that even a further miniaturization seems feasible.
On the Use of a Simplified New Product Development Process in an Early-Stage Firm
Authors: Marion Tucker J. , Simpson Timothy W.
Published: May 2009

Disciplined product development has been a hallmark of mature companies for many decades, resulting in shorter development cycles, reduced costs, and higher quality products. Unfortunately, these tools and processes have typically been applied in large, well-established firms, not start-up companies. In this paper, we describe a simplified new product development process for early-stage firms and its application to a consumer product in which the process was executed during a 14-month development cycle. The process consists of 15-steps in 3-phases, two decision gates, and provides a step-by-step guide for development, with specific call-outs as to what, when, and where tools such as market segmentation, platform planning, industrial design, and cost modeling should be applied. The proposed process is applied to design a new consumer product, and the case study results are discussed with specific emphasis on costs, duration, and applicability of the process and its related engineering tools. Finally, we conclude with comments on the limitations of the proposed process, potential improvements, and future work.
Roll to Roll Processing for Flexible Nanophotonics
Authors: Chang Fuh-Yu , Lin Hung-Yi , Lai Wen-Lang , Ting Chia-Jen , Tsai Jen-Hui , Chang Shuo-Hung , Wu Tung-Chuan
Published: May 2009

This article discusses the current status and achievements of R2R technology for large area nano-scaled optical devices developed at MSL/ITRI. Firstly, a single layer of nanostructure on polymer film is designed for anti-reflection purpose by finite difference time domain (FDTD) method in the visible light spectrum. The conical array with around 1 aspect ratio, like moth-eye shape and showing superior performance in the optical simulation, has been adapted for the R2R experiments. The development of R2R process includes roller machine design and fabrication, roller mold design and making, development of rolling imprint process, characterization of rolled devices. In this study, large area (200mm *200mm) Ni template was fabricated with DUV exposure, followed by dry etching and electroforming process, respectively. Then, the template was bonded on the roller mold with magnetic film to make nanostructure roller mold. With the delicate nanostructure roller mold, systematic experiments have been conducted on the home-made roller machine with various parameters, such as linear speed, dose rate, and material modifications. The duplicated nanostructure films show very good optical quality of anti-reflection (AR < 1%) and are in good agreement with the theoretical predictions. Besides, the duration of the roller mold has been highly promoted to hundreds of imprint in the UV embossing process.
Conceptual Design of a Carbon Nanotube Based Gearbox
Authors: Virk Gurjiwan , Singh Manvinder , Jain Vijay , Rao P. V. M.
Published: May 2009

Gears, bearings, springs, fasteners etc. are some typical machine elements used to build machines and mechanical systems. These elements are used for performing one or more of functions such as, to transmit motion, to support moving members, to store energy, to join two components etc. The continuous miniaturization and the need for mechanical systems having sizes of a few nanometers have led to new but challenging issues in design and manufacturing of these machine elements. Carbon nanotubes have a potential to be used as machine elements in multiple roles for building mechanical systems at a nano level. This paper explores the use of single-walled and multi-walled carbon nanotubes in building a nano-mechanical system such as gearbox. The paper presents a conceptual design of a gearbox completely made of carbon nano tubes and discusses its feasibility and realizability. The paper also discusses future directions of research in building nanomachines and nano-mechanical systems using carbon nanotube based machine elements.
An Evaluation of the Pugh Controlled Convergence Method
Authors: Frey Daniel D. , Herder Paulien M. , Wijnia Ype , Subrahmanian Eswaran , Katsikopoulos Konstantinos , Clausing Don P.
Published: May 2009

This paper evaluates a method known as Pugh Controlled Convergence and its relationship to recent developments in design theory. Computer executable models are proposed simulating a team of people involved in iterated cycles of evaluation, ideation, and investigation. The models suggest that: 1) convergence of the set of design concepts is facilitated by the selection of a strong datum concept; 2) iterated use of an evaluation matrix can facilitate convergence of expert opinion, especially if used to plan investigations conducted between matrix runs; and 3) ideation stimulated by the Pugh matrices can provide large benefits both by improving the set of alternatives and by facilitating convergence. As a basis of comparison, alternatives to Pugh’s methods were assessed such as using a single summary criterion or using a Borda count. The models we developed suggest that Pugh’s method, under a substantial range of assumptions, results in better design outcomes than those from these alternative procedures.
Studying the Dynamics of the Architecture of Software Products
Authors: Sosa Manuel E. , Browning Tyson , Mihm Ju¨rgen
Published: May 2009

This paper reports on an exploratory study of how the architecture of a software product evolves over time. Because software is embedded in many of today’s complex products, and it is prone to relatively rapid change, it is instructive to study software architecture evolution for general insights into product design. We use metrics to capture the intrinsic complexity of software architectures as they evolve through successive generations (version releases). We introduce a set of product representations and metrics that take into account two important features used to manage the complexity in software products: layers and modules. We also capture organizational data associated with the product under development. We propose a three-step approach for the analysis and illustrate it using successive versions of an open source product, Ant. One of our findings is that software architectures seem to evolve in a non-linear manner similar to the S-shaped curve that characterizes technology evolution at the industry level. We also find several parallel patterns among architectural and organizational dynamics. Implications for research and practice are discussed.
Methods for the Simulation of Micro Components With Respect to the Grain Structure
Authors: Albers Albert , Enkler Hans-Georg
Published: May 2009

The development of smaller and smaller micro components and systems is an ongoing process. Effects coming along with this process have to be investigated. A polycrystalline material consists of grains with different orientations. Therefore, a micromechanical model of a polycrystalline material for a Finite Element analysis should consider the grain structure. Studies show that with decreasing size of a micro component its grain structure and material anisotropy gain more and more influence on its stress, strain and flow of forces. In order to ensure a reliable dimensioning of micro components the influence of the grain structure and material’s anisotropy upon the stress and stress distribution has to be investigated. For this purpose, experimental work for characterizing materials’ properties is supplemented by numerical analyses. On the one hand, these analyses allow examining specific influences on the mechanical stress. On the other hand, micromechanical modeling has potential to increase the understanding of material behavior. Methods for modeling two- and three-dimensional micro components with complex grain structures including defects such as pores are presented and compared. The consideration of effects coming along with the grain structure makes a contribution to a reliable dimensioning of micro components with distinct grain structures.
A Comparison of Kinetostatic and Multibody Dynamics Models for Simulating Protein Structures
Authors: Su Hai-Jun , Parker Jesse , Kazerounian Kazem , Ilies Horea
Published: May 2009

This paper presents an initial comparison of two approaches to energy minimization of protein molecules, namely the Molecular Dynamic Simulation and the Kineto-Static Compliance Method. Both methods are well established and are promising contenders to the seemingly insurmountable task of global optimization in the protein molecules potential energy terrain. The Molecular Dynamic Simulation takes the form of Constrained Multibody Dynamics of interconnected rigid bodies, as implemented at the Virtual Reality Application Center from Iowa State University. The Kineto-Static Compliance Method is implemented in the Protofold Computer package developed in the Mechanical Engineering Department at the University of Connecticut. The simulation results of both methods are compared through the trajectory of potential energy, the Root Mean Square Deviation (RMSD) of the alpha carbons, as well as based on visual observations. The preliminary results indicate that both techniques are very effective in converging the protein structure to a state with significantly less potential energy. At present, the converged solutions for the two methods are, however, different from each other and are very likely different from the global minimum potential energy state.
Experimental Validation of a Squeeze-Film Damping Model Based on the Direct Simulation Monte Carlo Method
Authors: Sumali Hartono , Epp David S. , Torczynski John R. , Gallis Michael A.
Published: May 2009

A model for computing the force from a gas film squeezed between parallel plates was recently developed using Direct Simulation Monte Carlo simulations in conjunction with the classical Reynolds equation. This paper compares predictions from that model with experimental data. The experimental validation used an almost rectangular MEMS oscillating plate with piezoelectric base excitation. The velocities of the suspended plate and of the substrate were measured with a laser Doppler vibrometer and a microscope. Experimental modal analysis yielded the damping ratio of twelve test structures for several different gas pressures. Small perforation holes in the plates did not alter the squeeze-film damping substantially. These experimental data suggest that the model predicts squeeze-film damping forces accurately. From this comparison, it is seen that these structures have a tangential-velocity accommodation coefficient close to unity.
Metrics for Assessing Coupling Density and Modularity in Complex Products and Systems
Authors: Ho¨ltta¨-Otto Katja , de Weck Olivier
Published: May 2009

The central role of modularity is becoming more and more apparent in design of complex products and systems. The question frequently arises how modularity can be measured. To better understand the degree of modularity, we developed two metrics based on a design structure matrix (DSM). The non-zero fraction (NZF) captures the coupling density of interconnections between components, while the singular value modularity index (SMI) measures the degree of modularity. Both metrics yield values between 0 and 1. These metrics are applied to 15 systems and products. We show that real products typically have NZF values between 0.05 and 0.4 and an SMI between 0.05 (very integral) and 0.95 (very modular). A randomly generated DSM population of equal size and density exhibits SMI values that are bounded in the range from 0.25 to 0.45. We conclude that neither a high degree of modularity nor strong integrality occurs accidentally; but are the result of deliberate design. In particular, we show a more integral design will emerge if a functionally-equivalent product is designed to be portable. The main advantage of SMI is that it enables analysis of the degree of modularity of any product or system independent of subjective module choices.
Metaphors in Conceptual Design
Authors: Hey Jonathan H. G. , Agogino Alice M.
Published: May 2009

A metaphor allows us to understand one concept in terms of another, enriching our mental imagery and imbuing concepts with meaningful attributes. Metaphors are well studied in design, for example, in branding, communication and the design of computer interfaces. Less well appreciated is that our understanding of fundamental design concepts, including design itself, is metaphorical. When we treat design as a process of exploration or when we get together to “bounce ideas off each other” we understand the abstract concepts of design and ideas metaphorically; ideas don’t literally bounce, nor are we literally exploring when we design. Our research is a descriptive study of the metaphors employed in design. It is the first phase in a longer research effort to understand the impact of design metaphors on creativity. We investigated whether design authors employed different metaphors for the overall design process and consequently for core design concepts. To address this hypothesis we analyzed the language used in the concept generation chapters of nine widely used engineering design textbooks. We coded each metaphorical phrase, such as “finding another route to a solution”, and determined the core metaphors in use for common design concepts including, ideas, problems, solutions, concepts, design, the design process, user needs and others. We confirmed that authors with differing views of design do indeed emphasize different metaphors for core design concepts. We close by discussing the implications of some common metaphors, in particular that Ideas Are Physical Objects.
Design for Transformation: Theory, Method and Application
Authors: Singh Vikramjit , Walther Brandon , Krager Jarden , Putnam Nathan , Koraishy Babar , Wood Kristin L. , Jensen Dan
Published: May 2009

Products which transform to reveal new functionality have been a source of fascination and utility for ages. Such products — transformers — have been previously designed employing ad hoc creativity rather than by pursuing any formal design methodology. By incorporating a design methodology and a concept generation tool for transformers, this research not only unearths further utility for these innovative and revolutionary products, but also aids engineers in the design of these devices with dexterity. The success and advantages of transformers result from added functionality while simultaneously using fewer resources and occupying less space. This paper elucidates the foundation of a methodology for the design of such transforming devices. Our basic research on transforming systems involves a combined inductive and deductive approach, uncovering transformation design principles and a novel method for designing transforming products. In the early stages of design, this method employs a unique process to extract customer needs by examining the requirement hierarchy of product usage scenarios. Such an approach broadens the scope of design and aids in identifying opportunities for transforming products while developing process level insights and solutions catering to these needs. During the concept generation phase of design, the method exploits the transformation design principles as a novel tool to complement and expand contemporary concept generation techniques. A unique bicycle accessory which transforms from a lock to a pump and vice versa is provided as an example of the transformational design process.
Cognitive Models of Design Ideation
Authors: Vargas Hernandez Noe , Shah Jami J. , Smith Steven M.
Published: May 2009

The objective of this paper is to present a series of proposed cognitive models for specific components of design ideation. Each model attempts to explain specific cognitive processes occurring during ideation. Every model presented here is constructed with elements (i.e. cognitive processes) and theories available from cognitive psychology, human problem solving, mental imagery, and visual thinking. Every model in turn is an element of a higher-level cognitive model of design ideation. These models provide a better understanding of the components involved during ideation and their relationships.
Modelling of Road Damage Potentials of Tandem C-Dolly
Authors: Romero Jose A. , Lozano Alejandro
Published: May 2009

The paper deals with the pavement damage potential of long combination vehicles equipped with tandem C-dolly. Due to its double-hitch bar design, the tandem C-dolly enhances the lateral stability of the articulated vehicles; however, its single articulation could create significant levels of longitudinal load transfer between the coupled bodies and posing higher pavement damage. The pavement damage potentials of vehicles equipped with tandem C-dolly is compared with that of vehicles equipped with standard tandem A-dolly. For pavements with a roughness lower than 2 mm/m the effect of tandem design is only marginal. For pavements with roughness greater than 2 mm/m, results suggest an optimum speed (95 km/h) at which C-dolly is 1% less damaging than A-dolly. However, for the other two speeds evaluated (75 and 115 km/h), C-dolly is up to 12.1% less friendly than A-dolly. Such increases in road damaging potential are significant and an experimental study should be performed to validate results.
Increasing Innovation: A Trilogy of Experiments Towards a Design-by-Analogy Method
Authors: Linsey J. S. , Laux J. P. , Clauss E. , Wood K. L. , Markman A. B.
Published: May 2009

Design by analogy is a noted approach for conceptual design. This paper seeks to develop a robust design-by-analogy method. This endeavor is sought through a series of three experiments focusing on understanding the influence of representation on the design-by-analogy process. The first two experiments evaluate the effects of analogous product description—presented in either domain-general or domain-specific language—on a designer’s ability to later use the product to solve a novel design problem. Six different design problems with corresponding analogous products are evaluated. The third experiment in the series uses a factorial design to explore the effects of the representation (domain specific or general sentinel descriptions) for both the design problem and the analogous product on the designer’s ability to develop solutions to novel design problems. Results show that a more general representation of the analogous products facilitates later use for a novel design problem. The highest rates of success occur when design problems are presented in domain specific representations and the analogous product is in a domain general representation. Other insights for the development of design by analogy methods and tools are also discussed.
Accelerating Development of a MEMS Piezoelectric Microphone
Authors: Lamers Tina L. , Fazzio R. Shane
Published: May 2009

MEMS projects are well known for their lengthy development times, hindering a company’s ability to make MEMS product development profitable. This paper describes a three-pronged methodology for rapid development of a piezoelectric MEMS microphone, utilizing concurrent design and prototyping, leveraged process technology, and a modified version of Quality Function Deployment (QFD). Avago Technologies has produced more than 300 million Film Bulk Acoustic Resonator (FBAR) piezoelectric band pass filters. FBAR uses Aluminum Nitride (AlN) as the piezoelectric film. Volume production of FBAR makes Avago the world’s only high volume producer of thin-film AlN products. This high-volume FBAR production process was greatly leveraged to enable fast prototyping of piezoelectric MEMS microphones. The concurrent design concept of simultaneously iterating on technical theory, finite element modeling, and prototyping with confirmation from testing was employed as another means of enabling swift development progress. QFD helps designers utilize the ‘voice of the customer’ to determine which product specifications are the most essential, and has long been used as a successful design methodology in the heavy industrial and automotive industries [1]. QFD and most other design methodologies have rarely been applied to MEMS products [2]. The second phase of QFD was modified for better application to MEMS products. Both Phase I and Phase II of QFD were then employed to guide the development process, giving insight into which elements of the design to focus on, which design concepts had the most merit, and which potential applications were the best fit to the technology. The combined effect of these three methods was extremely rapid development, enabling prototyping of hundreds of design variations and brisk improvement of measured results during the first eight months of the program. Achieving technical results quickly while assessing potential applications can aid in identifying a fast path to market. The methods used in this case study can easily be generalized for application to other MEMS development programs, potentially enabling MEMS products to reach production more quickly and generate increased profitability through addressing applications that best fit the technology and design.
Simultaneous On-Chip Sensing and Actuation Using the Thermomechanical In-Plane Microactuator
Authors: Waterfall Tyler , Teichert Kendall , Jensen Brian
Published: May 2009

Many applications in microelectromechanical systems require physical actuation for implementation or operation. On-chip sensors would allow control of these actuators. This paper presents experimental evidence showing that a certain class of thermal actuators can be used simultaneously as an actuator and a sensor to control the actuator’s force or displacement output. By measuring the current and voltage supplied to the actuator, a one-to-one correspondence is found between a given voltage and current and a measured displacement or force. This truly integrated sensor/actuator combination will lead to efficient, on-chip control of motion for applications including microsurgery, biological cell handling, and optic positioning.
Chaos Control in Single Mode Approximation of T-AFM Systems Using Nonlinear Delayed Feedback Based on Sliding Mode Control
Authors: Sadeghian Hoda , Arjmand Mehdi Tabe , Salarieh Hassan , Alasty Aria
Published: May 2009

The taping mode Atomic Force Microscopic (T-AFM) can be properly described by a sinusoidal excitation of its base and nonlinear potential interaction with sample. Thus the cantilever may cause chaotic behavior which decreases the performance of the sample topography. In this paper a nonlinear delayed feedback control is proposed to control chaos in a single mode approximation of a T-AFM system. Assuming model parameters uncertainties, the first order Unstable Periodic Orbits (UPOs) of the system is stabilized using the sliding nonlinear delayed feedback control. The effectiveness of the presented methods is numerically verified and the results show the high performance of the controller.
Nonlinear Dynamics and Control of the Scan Process in Atomic Force Microscopy
Authors: Hornstein S. , Gottlieb O.
Published: May 2009

Atomic Force Microscopy (AFM) is a major imaging tool used to map surfaces down to atomic resolution. However, scanning rates in AFM are still low, and attempts to increase the speed usually end up with low-resolution pictures. In order to address this deficiency we propose a novel model that treats the scanning element as a moving continuous microcantilever, which undergoes a combined spatial motion in both the horizontal and the vertical directions. This research investigates the effect of increasing the scan speed on the dynamics and stability of a vibrating microcantilever that is governed by a specified control law. We reduce the spatio-temporal model to a rigid body two-degrees-of-freedom system, which is connected to a linear digital controller. Results demonstrate that the digital controller stabilizes the nonlinear system and enables a smooth transition from one side to the other side of the sample, needed for the scanning process.
Contribution to the Mechanical Behavior Improvement of the Robotic Navigation Device Surgiscope®
Authors: Briot Se´bastien , Baradat Ce´dric , Gue´gan Sylvain , Arakelian Vigen
Published: May 2009

This paper proposes a new solution to the problem of torque minimization of the medical device SurgiScope® by connecting to the initial structure a secondary mechanical system, which generates a vertical constant force on the platform of the robotized device. The conditions for optimization are formulated by the minimization of the root-mean-square values of the input torques of the studied device. The positioning errors of the unbalanced and balanced robots are provided. A significant reduction of these errors is achieved by using the suggested balancing mechanism. The efficiency of the developed approach is illustrated by numerical simulations. Experimental validation of the obtained optimization is illustrated by a prototype developed in the National Institute of Applied Sciences of Rennes in collaboration with the “Intelligent Surgical Instruments & Systems” (ISIS) Company.
Sensitivity Analysis in Perceptual Evaluation of System Module Concepts
Authors: Takai Shun , Ishii Kosuke
Published: May 2009

Selecting optimum concepts for a system and its subsystems in the conceptual design stage involves uncertainties due to imperfect information about customer preferences (market shares), cost of the system developed from each concept, and feasibility of new technology used in the new system. When analytical relationships between system performance and system inputs or parameters are unknown in the early system development stage, one approach to quantify the goodness of a concept is to use rating scales. This paper studies the effects of variations (precisions) in rating scales and in cost estimation for evaluating the goodness of system module concepts (e.g., sub-systems, assemblies, subassemblies, and parts). This paper presents a global sensitivity analysis (GSA) in perceptual concept evaluation, three probability measures for evaluating and selecting optimum concepts in GSA, and one-set-of-factors-at-a-time GSA to identify the sets of factors that cause significant variations in concept evaluation outcomes.
Analytical Representation of Nano-Scale Parasitic Motion in Flexure-Based Selectively Compliant Mechanisms
Authors: Patil Chinmaya B. , Sreenivasan S. V. , Longoria Raul G.
Published: May 2009

Analytical modeling of selectively compliant mechanisms for quantifying the nano-scale parasitic motion is presented. Flexure-based compliant mechanisms are capable of meeting the demanding requirements of the partially constrained ultraprecision motion systems. However, the geometric errors induced by manufacturing tolerances can limit the precision capability. Understanding parasitic motion at the nano-scale necessitates a 3-D model even for mechanisms that are designed to be planar. A spatial kinematics based kinetostatic model is used here. This approach systematically accounts for the geometric errors, and enables estimation of the inherently spatial parasitic motion. Using insights from screw theory, the parasitic motion is classified into intrinsic mechanism errors, and errors that can be minimized by calibration procedures. A metric that quantifies the intrinsic parasitic motion and characterizes the precision capability of the mechanism is identified. Monte Carlo simulation is used to propagate the variance of the geometric errors through the model to determine the statistical moments of the chosen metric. To illustrate the approach, the modeling and analysis is applied to a classical four-bar mechanism with flexure joints. The model is further used to investigate the key system parameters that influence the intrinsic parasitic motion in the mechanism. The simulation results indicate more than 50% improvement in the precision capability of the four-bar mechanism by improved design of flexure joints, without changing the manufacturing tolerance limits.
Control Algorithm for Nanoscale Positioning of a 6DOF Stewart Platform
Authors: Ting Yung , Jar Ho-Chin , Li Chun-Chung
Published: May 2009

A 6DOF Stewart platform driven by piezoelectric actuators was designed for applications in need of nanoscale positioning. By using flexural joints and an error compensation model based on a minimum-points-3-axes measurement method, the manufacturing and assembly errors can be offset. The design of a feedforward controller that is able to reduce the nonlinear hysteresis effect of the piezoelectric actuator is the focus of this article. A dynamic Preisach model is developed to improve the accuracy of hysteresis model, whose inverse model is used as the feedforward controller. Such a control scheme is cost-effective without employing expensive sensors for feedback control. Experimental data shows that the platform can achieve the objective of nanoscale positioning.
Technology Change Analysis for Product and Product Platform Design
Authors: Khadke Kiran , Gershenson John K.
Published: May 2009

In designing products and product platforms, it is essential to consider the role of technology evolution to avoid frequent redesign costs or even premature obsolescence of key components. Taking this into account in multi-generational design is referred to as planned product innovation. The existing design tools/processes fail to delineate different technologies and therefore capitalize on ways of technological change within products. This paper provides a framework for technology change analysis by identifying underlying technologies and the potential for change in their intrinsic characteristics — performance level, principle of operation, and technology architecture. Measuring the three aspects of technological change separately and comparing them to their respective forecast information yields a technology’s potential for planned innovation. The technology change framework can be applied to an initial design of the product that is anticipated to undergo planned innovation. A detailed function-structure diagram and a component-based design structure matrix of the initial product design serve as inputs to the framework and result in technology change potentials for each technology. Grouping components with similar technology change potentials (in all three aspects) into independent clusters will allow organizations to focus their development efforts on clusters that are most ripe for innovation with minimal disruption to the rest of the product. For product platform identification, the technology change framework is used to develop a set of four heuristics to identify technology-based platform elements. The set of four heuristics require that the platform elements have a low potential for change in performance level, principle of operation, and technology architecture or have standardized interfaces. Having a technology focus for product platforms is necessary as forecasting and diffusion models/studies are available at a technology level rather than at an individual component level. Localization of any anticipated platform or family changes due to technology evolution (through platform formation) will minimize redesign changes and the cascade of disruptions in each variant. Future work will focus on developing step-by-step methods for technology-based clustering of products and integrating the technology-based platform elements with other market-based and function-based platform methods to truly yield a flexible and robust product platform design method.
Design Methods, Tools, and Outcome Measures: A Survey of Practitioners
Authors: Yang Maria C.
Published: May 2009

Several tools and methods drawn from research in design and manufacturing have been successfully transplanted into industry. This paper describes a survey conducted of practicing designers and engineers in fields ranging from product development to aerospace to better understand the methodologies and metrics they employ. Preliminary results suggest that respondents found methodologies such as need finding, storyboarding, and brainstorming useful, but were less familiar with approaches such as systematic design, axiomatic design, or TRIZ. There was wide variation in what respondents felt were appropriate design outcome measures, but positive customer feedback in particular was deemed important in evaluating project performance. Finally, a broad range of design tools was cited as useful by respondents, but computer aided drawing applications in particular were rated highly. It is hoped that this survey can be of value in formulating future research goals in design theory and tool development.