Micro and Smart Systems

Micro and Smart Systems

G.K. Ananthasuresh, K.J. Vinoy, S. Gopalakrishnan, K.N. Bhat, V.K. Aatre

ISBN: 13: 978-81-265-2715-1

Publication Date: August 2010

Price: INR 379/Pages: 420

 

About the Technology

If we trace the history of electronic technology over the last six decades, we see that the discovery of the transistor and the development of the integrated circuit (IC) are the key milestones. However, it is the miniaturization and the ensuing VLSI technology that really created the electronic, the computer and communications revolution. It is only more recently, i.e., in the last couple of decades, that the technology of miniaturization has been extended to mechanical systems; and now, we have microsystem revolution. This is also complemented by the advances in smart materials and systems.

A microsystem is a system that integrates, on a chip or in a package, one or more of many microdevices: sensors, actuators, electronics, computation, communication, control, power generation, chemical processing, biological reactions, and many more which constitute microsystems. It is now clear that the functionality of such an integrated system will be not only far superior to any other engineered system that we know at the macro scale but achieve things beyond those achievable by macro-scale integrated systems. Smart micro electromechanical systems (MEMS) refer to a collection of micro sensors and actuators that can sense their environment and have the ability to react to changes in that environment with the use of a microcircuit control. Such microsystems include, in addition to the conventional microelectronics, packaging, integrated antenna structures for command signals, microelectromechanical structures for desired sensing and actuating functions. In order to act upon the environment, the magnitude of the micromachined actuators is not large enough. Using macro-scale actuators is not appropriate because they defeat the purpose of miniaturization, cost-effective batch-processing, etc. Hence, there is a need to integrate smart material based actuators with microsystems. This trend is currently witnessed in this field as it moves beyond microsensors, which has been the main emphasis in microsystems so far.

Micro and smart system technologies have immense application potential in many fields. In the coming decades, scientists and engineers would be required to design and develop such systems for varied applications. It is essential then that graduating engineers must be exposed to the underlying science and technology.

Key Features

• This book emphasizes analytical and computational modeling.
• It includes in-depth discussion of mechanics, coupled multi-physics, electronics, control, and scaling effects as well as finite element analysis.
• Relating all of the above to particular examples of microelectromechanical systems (MEMS) and smart devices is a highlight of this book.
• Complementing the modeling aspects, the book includes organized summaries of a variety of devices and systems, details of packaging and integration, and case-studies of representative devices.
• Prior disciplinary background is not assumed in presenting the material.
• Many worked-out examples, context-relevant problems within the chapters, and practice exercises are included in all chapters. It is thus suitable for self-study by practicing engineers and researchers in many disciplines.
• Unavailability of a book that covers both micro and smart systems at the fundamental level.
• Excellent pedagogy with:

• 230+ Illustrations
• 25 Tables
• 100+ Exercise Questions
• 45 “Your Turn” questions for students wanting to invest time in researching.
• About 50 Problems and Examples within chapters 

About the Book

This book essentially deals with the basics of microsystem technology and is intended principally as a textbook at the undergraduate level; however, it can also be used as background book at the postgraduate level. The book makes an effort to provide an introduction to smart materials and systems. The authors make an attempt to present the material without assuming much prior disciplinary background. The aim of this book is to present adequate modeling details so that readers can appreciate the analysis involved in microsystems (and to some extent, smart systems) and thereby enabling them to get an in-depth understanding about simulation and design. Therefore, the book will also be useful to practicing researchers in all branches of science and engineering, who might be interested in applications where they can use this technology. The book presents adequate details of modeling of microsystems as well as addresses their fabrication and integration.  The engineering of practical applications of microsystems are areas for multidisciplinary research, already laden with myriad technological issues.  Evidently, books presently available do not address many of these aspects sufficiently well. We believe that this book gives a unified treatment of the necessary concepts under a single title.

                Anticipating the need for such a technology, the Institute of Smart Structures and Systems (ISSS), an Institute dedicated to promoting the field of smart materials and microsystems, was established. This Institute was not only instrumental in mounting a national program, triggering R&D activities in this field in India but also creating required human resource through training courses and workshops. Furthermore, ISSS also initiated a dialogue with Visvesveraya Technological University (VTU), Belgaum, Karnataka, a conglomerate of over 170 engineering colleges in Karnataka, for introducing a course at the undergraduate level in the area of microsystems and MEMS and for setting in motion drafting potential syllabus for the same. The culmination of this dialogue is this book. Material for this book has been taken from several advanced workshops and short courses conducted by the authors over last three years for faculty and students of VTU. A draft of the preliminary version of book was used by VTU colleges, where a course on microsystems was first introduced in 2009.  The current version is modified to incorporate feedback received from teachers of this course, who patiently used the previous draft to teach about 500 students from various colleges. In a sense this book has been class- and student-tested.

  This book has nine chapters covering various topics in microsystems and smart systems including sensors and actuators, microfabrication, modeling, finite element analysis, modeling and analysis of coupled systems which is of great importance in microsystems, electronics and control for microsystems, integration and packaging, and scaling effects in microsystems. The book also includes case studies on a few microsensor systems to illustrate the application aspects. 

About the Authors

All the authors of this book are stalwarts in their respective field and are key people in promoting the technology and subject. 

Prof. G.K. Ananthasuresh (B.Tech., IIT Madras, 1989; PhD, Michigan, 1994) is a Professor of Mechanical Engineering in the IISc, Bangalore, India. He has been working in the microsystems area since 1991 with emphasis on modeling and design. Prof. Ananthasuresh has edited the first book on Optimal Synthesis Methods for MEMS.

Prof. K.J. Vinoy (B.Tech., Kerala, 1991; M.Tech., Cochin, 1992; PhD, Pennsylvania State 2002) is an Associate Professor in the Department of Electrical Communication Engineering at the IISc, Bangalore. This is his third book in the area of Microsystems. 

Prof. Gopalakrishnan (B.E., Bangalore, 1984; M.Tech., IIT Madras, 1987; PhD, Purdue 1992) is a Professor in the Department of Aerospace Engineering at IISc. He is a Fellow of INAE. Prof. Gopalakrishnan is the Chairman of the Aerospace Applications and Structural Health Monitoring group of the National Programme on Micro and Smart Systems.

Prof. K.N. Bhat (B.E., IISc Bangalore, 1966; M.Eng., Rensselaer 1974; PhD, IIT Madras, 1978) was a professor at IIT Madras and is currently a Visiting Professor at IISc. He is a Fellow of the INAE. He has immensely contributed to the growth of VLSI and MEMS technology, Education and Manpower development in India.

Prof. V.K. Aatre (B.E., Mysore, 1961; M.E., IISc Bangalore 1963; PhD, Waterloo, 1967) was the Director General of DRDO and Scientific Adviser to the Defence Minister, Government of India.  He is a Fellow of IEEE and INAE and is a recipient of the prestigious Padma Bhushan Award in India. He initiated two national programmes on Micro and Smart Systems founded the Institute of Smart Structures and Systems (ISSS). 

Table of Contents 

1    Introduction

1.1   Why Miniaturization?

1.2   Microsystems versus MEMS

1.3   Why Microfabrication?

1.4   Smart Materials, Structures and Systems

1.5   Integrated Microsystems

1.6   Applications of Smart Materials and Microsystems

1.7 Summary

References 

2   Micro Sensors, Actuators, Systems and Smart Materials: An Overview

2.1   Silicon Capacitive Accelerometer

2.2   Piezoresistive Pressure Sensor

2.3   Conductometric Gas Sensor

2.4   An Electrostatic Comb-Drive

2.5   A Magnetic Microrelay

2.6   Portable Blood Analyzer

2.7   Piezoelectric Inkjet Print Head

2.8   Micromirror Array for Video Projection

2.9   Smart Materials and Systems

2.10 Summary

References

Exercises 

3   Micromachining Technologies

3.1   Silicon as a Material for Micromachining

3.2   Thin-Film Deposition

3.3   Lithography

3.4   Etching

3.5   Silicon Micromachining

3.6   Specialized Materials for Microsystems

3.7   Advanced Processes for Microfabrication

3.8   Summary

References

Further Reading

Exercises 

4.  Modeling of Solids in Microsystems

4.1 The Simplest Deformable Element: A Bar

4.2 Transversely Deformable Element: A beam

4.3 Energy Methods for Elastic Bodies

4.4 Examples and Problems

4.5 Heterogeneous Layered Beams

4.6 Bimorph Effect

4.7 Residual Stresses and Stress Gradients

4.8 Poisson Effect and the Anticlastic Curvature of Beams

4.9 Torsion of Beams and Shear Stresses

4.10 Dealing with Large Displacements

4.11 In-Plane Stresses

4.12 Summary

Further Reading

Exercises 

5  Finite Element Method

5.1 Need for Numerical Methods for Solution of Equations

5.2 Variational Principles

5.3 Weak Form of the Governing Differential Equation

5.4 Finite Element Method

5.5 Numerical Examples

5.6 Finite Element Model for Structures with Piezoelectric Sensors and Actuators

5.7 Analysis of a Piezoelectric Bimorph Cantilever Beam

5.8 Summary

References

Exercises 

6   Modeling of Coupled Electromechanical Systems

6.1 Electrostatics

6.2 Coupled Electromechanics: Statics

6.3 Coupled Electromechanics: Stability and Pull-In Phenomenon

6.4 Coupled Electromechanics: Dynamics

6.5 Squeezed Film Effects in Electromechanics

6.6 Summary

References

Further Reading

Exercises 

7  Electronics Circuits and Control for Micro and Smart Systems

7.1 Semiconductor Devices

7.2 Electronics Amplifiers

7.3 Practical Signal Conditioning Circuits for Microsystems

7.4 Circuits for Conditioning Sensed Signals

7.5 Introduction to Control Theory

7.6 Implementation of Controllers

7.7 Summary

References

Exercises 

8   Integration of Micro and Smart Systems

8.1 Integration of Microsystems and Microelectronics

8.2 Microsystems Packaging

8.3 Case Studies of Integrated Microsystems

8.4 Case Study of a Smart Structure in Vibration Control

8.5 Summary

References

Exercises 

9  Scaling Effects in Microsystems

9.1 Scaling in the Mechanical Domain

9.2 Scaling in the Electrostatic Domain

9.3 Scaling in the Magnetic Domain

9.4 Scaling in the Thermal Domain

9.5 Scaling in Diffusion

9.6 Scaling in Fluids

9.7 Scaling Effects in the Optical Domain

9.8 Scaling in Biochemical Phenomena

9.9 Summary

Further Reading

Exercises 

Glossary

Index

About the Authors

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