This paper presents a systematic analysis of the sensitivity of design parameters of a microchannel to the onset of the slip effect. This is motivated because design geometries of microsystems cannot be simply downscaled, because at small dimensions inertia and gravity do not necessarily remain the dominant forces, and the behavior of the microsystem to be designed changes. This is particularly important in the design of MEMS involving fluids, where friction in the form of an inversion layer becomes effective. While such characteristics are often exploited in clever design, it is not always known when such effects take place, because they are be the consequence of different combinations of parameters, often represented implicitly as a single quantity: the Reynolds number. However the Reynolds number on its own cannot be controlled, it does not tell us about the sensitivity of the parameters. In our endeavor of developing fast models that are suitable for interactive CAD VR we are interested in the conditions that mark the onset of the dominance of one physical effect over another. To this end we have initiated a systematic set of experiments to calculate the fluid flow for a square and round channel in a systematic way by changing systematically the critical parameters (channel length, side length or diameter, and pressure) including the calculation of the slip effect as an additional term that allows seeing in which combinations it becomes effective.
This paper presents the design of a Graphical User Interface for a MEMS CAD tool that addresses the weaknesses of some existing CAD tools for MEMS design. MEMS design is a complex process where many disciplines, processes, materials and structures come together. Consequently, the MEMS CAD tools available are sophisticated and complex tools. The complexity of these tools often exceeds the effectiveness, resulting in unwieldy user interface designs. This in turn impacts the usability of these software packages. We have developed the Task-oriented User Interface Design architecture to address complex system design issues that are inherent in MEMS CAD tools. With this architecture we are able to reduce visual clutter on the screen without loss of functionality, at the same time allowing quick switching between tasks. The architecture is extensible, making it easy to add more MEMS design facilities to the CAD tool.
As MEMS devices are finding more application areas and new devices are developed, the designs of MEMS are becoming more complex. Without computer aid, designers have to rely on experiment and it becomes time consuming. There are a few commercial MEMS design tools are available currently, however these design tools have their limitations. This paper presents the work towards a user friendly MEMS Virtual Reality MEMS CAD tools that models, simulates, and provides the behavior characteristics and virtual reality visualization of MEMS devices. In this part of the project - the sensor component, we analyze the requirements for modeling MEMS sensors by investigating several types of MEMS, their operating characteristics and their corresponding design parameters. An application example serves to illustrate the analysis and applicability of the models in the sensors component, and to investigate its interaction with other components such as user interface, VR animation, and manufacturing module.
The pleasing and intuitive visualization images of Micro-Electro-Mechanical Systems (MEMS) assist microtechnology researchers and designers extract significant features and results quickly and easily. The detailed visualization through different points of view may reduce a MEMS design trial and error phase for system elements dimension and placement. The work presented in this paper is part of a research project for developing MEMS Virtual Reality prototyping software. The objective of the project is to build a simulation environment that aids in the MEMS design. Scientific visualization design tools make it easier for MEMS designers to view their results functioning in 3D Virtual Reality on a computer screen before shaping a physical prototype. This paper discusses the issues that are relevant in the development of producing the MEMS VR images and their animations. The images for applying visualization and Virtual Reality to demonstrate a sensor and an actuator are shown.
The MEMS Virtual Prototyping project aims at building a simulation environment that aids in the design of MicroElectroMechanical devices (MEMS). It embodies Computer-Aided Design (CAD) tools for modeling and simulating the functioning of MEMS in virtual reality and to provide visualizations of their performance as multi-parameter functions as virtual reality visualizations and as plots, both based on analytical calculations. The introduction of CAD packages was a critical step in the widespread development of VLSI devices. Despite the demand, there is a noticeable lack of CAD tools to aid in the development of MEMS devices. The purpose of the project presented in this paper is to overcome the weaknesses of the few MEMS-CAD tools that are available. This project analyzes the fundamental steps towards (a) determining critical parameters for typical classes of MEMS (sensors and actuators) (b) identifying visualizations that are meaningful in the MEMS design process, and (c) a novel graphic user-interface architecture to facilitate task switching in CAD-tools, and reducing screen clutter. This paper also describes the Manufacturing module, it explains Visual Design Optimization and provides an application example.
The design stage of the development of a MEMS device is crucial if its fabrication is to be right the first time. Computer-aided design (CAD) helps to accelerate this process and provides a cost-effective method in the prediction and optimization of device characteristics. This paper describes this design process, focusing on the conceptual design phase in the development of microactuators as part of the actuator component of a Virtual Reality-prototyping CAD tool. To create the functions and database required for this tool, the effects of parameters such as temperature, pressure, strain, acceleration etc., on the microactuator have to be evaluated. To achieve this, a comprehensive analysis of the most relevant parameters affecting the different types of microactuators based on their force-producing principle is required. This is a huge and lengthy task. It includes the estimation of mechanical performance of the device with variation in its geometrical structure and the optimization of the variations with respect to their static and dynamic performance, for example linearity and resonant frequency. It aids in the analysis of constraints in the geometrical design for robustness in its manufacture. In this paper we analyze the requirements, the functions and database entries, via an application case example for a membrane micropump. Its structure is studied in order to demonstrate the feasibility of using this device as a pump that is able to move air from one chamber to another. In this example we look at the underlying models that warrant a desired performance and whose calculations results in the geometries and operational parameters, such as the flow of air or liquid, the deflection of the membrane, etc. These results serve as input to the Virtual Reality Visualizations module and displayed with time and size scaled animations.
Finite State Machines (FSM) are models for functions commonly implemented in digital circuits such as timers, remote controls, and vending machines. Teaching FSM is core in the curriculum of many university digital electronic or discrete mathematics subjects. Students often have difficulties grasping the theoretical concepts in the design and analysis of FSM. This has prompted the author to develop an MS-WindowsTM compatible software, WinState, that provides a tutorial style teaching aid for understanding the mechanisms of FSM. The animated computer screen is ideal for visually conveying the required design and analysis procedures. WinState complements other software for combinatorial logic previously developed by the author, and enhances the existing teaching package by adding sequential logic circuits. WinState enables the construction of a students own FSM, which can be simulated, to test the design for functionality and possible errors.
A study to investigate systematic ways of controlling parametric yield for future production of deep submicron MOSFETs has been performed. It is important to know how and where in the manufacturing process the parametric yield can be controlled most efficiently, because for these devices no manufacturing expertise has yet been accumulated. Our study is based on a comparative sensitivity analysis, which has revealed that yield control techniques employed in micron size devices may not be efficient in deep submicron size devices, making a reorientation for manufacturing control mandatory.
As an extension to approaches in wafer processing, a new technique is being developed: Dynamic Design Processing. This technique is based on the recalculation of design specifications, whenever the results of any process step diverge specifications. These random divergences are inherent in any processing step. Recalculation of the design specification values restores the final performance of the device to the desired one. Simulation results show that applying this technique is practically equivalent to eliminating the process randomness.