ECT362 Introduction to MEMS

Course Outcomes

CO1 Describe the working principles of micro sensors and actuators
CO2 Identify commonly used mechanical structures in MEMS
CO3 Explain the application of scaling laws in the design of micro systems
CO4 Identify the typical materials used for fabrication of micro systems
CO5 Explain the principles of standard micro fabrication techniques
CO6 Describe the challenges in the design and fabrication of Micro systems

MODULE I
MEMS and Microsystems: Applications – multidisciplinary nature of MEMS – principles and examples of Micro sensors and micro actuators – micro accelerometer –comb drives – Micro grippers – micro motors, micro valves, micro pumps, Shape Memory Alloys.
Actuation and Sensing techniques: Thermal sensors and actuators, Electrostatic sensors and actuators, Piezoelectric sensors and actuators, magnetic actuators
MODULE II
Review of Mechanical concepts: Stress, Strain, Modulus of Elasticity, yield strength, ultimate strength – General stress strain relations – compliance matrix. Overview of commonly used mechanical structures in MEMS – Beams, Cantilevers, Plates, Diaphragms – Typical applications
Flexural beams: Types of Beams, longitudinal strain under pure bending – Deflection of beams – Spring constant of cantilever – Intrinsic stresses
MODULE III
Scaling laws in miniaturization – scaling in geometry, scaling in rigid body dynamics, Trimmer force scaling vector, scaling in electrostatic and electromagnetic forces, scaling in electricity and fluidic dynamics, scaling in heat conducting and heat convection.
Materials for MEMS – Silicon – Silicon compounds – Silicon Nitride, Silicon Dioxide, Silicon carbide, Poly Silicon, GaAs , Silicon Piezo resistors. Polymers in MEMS – SU-8, PMMA, PDMS, Langmuir – Blodgett Films.

MODULE IV
Micro System fabrication – Photolithography – Ion implantation- Diffusion – Oxidation – Chemical vapour deposition – Etching
Overview of Micro manufacturing – Bulk micro manufacturing, Surface micro machining, LIGA process –Microstereo lithography
MODULE V
Micro system Packaging: general considerations in packaging design – Levels of Micro system packaging. Bonding techniques for MEMS: Surface bonding, Anodic bonding, Silicon – on – Insulator, wire bonding, Sealing – Assembly of micro systems. Overview of MEMS areas : RF MEMS, BioMEMS, MOEMS, NEMS

Text Books:
1. Chang Liu, Foundations of MEMS, Pearson 2012
2. Tai-Ran Hsu, MEMS and Microsystems Design and Manufacture, TMH, 2002
Reference Books:
1. Chang C Y and Sze S. M., VLSI Technology, McGraw-Hill, New York, 2000
2. Julian W Gardner, Microsensors: Principles and Applications, John Wiley & Sons, 1994
3. Mark Madou, Fundamentals of Micro fabrication, CRC Press, New York, 1997
4. Stephen D. Senturia, Microsystem design, Springer (India), 2006.
5. Thomas B. Jones, Electromechanics and MEMS, Cambridge University Press, 2001
6. Gregory T.A. Kovacs, Micromachined Transducers Sourcebook, McGraw Hill, 1998