19-09-2012, 03:19 PM
MEMS and MICROSYSTEMS DESIGN AND MANUFACTURE
MEMS and MICROSYSTEMS.pdf (Size: 1.57 MB / Downloads: 336)
WHAT IS MEMS?
MEMS = MicroElectroMechanical System
Any engineering system that performs electrical and mechanical functions
with components in micrometers is a MEMS. (1 μm = 1/10 of human hair)
Available MEMS products include:
● Micro sensors (acoustic wave, biomedical, chemical, inertia, optical,
pressure, radiation, thermal, etc.)
● Micro actuators (valves, pumps and microfluidics;
electrical and optical relays and switches;
grippers, tweezers and tongs;
linear and rotary motors, etc.)
● Read/write heads in computer storage systems.
● Inkjet printer heads.
● Micro device components (e.g., palm-top reconnaissance aircrafts, mini
robots and toys, micro surgical and mobile telecom equipment, etc.)
Miniaturization Makes Engineering Sense!!!
• Small systems tend to move or stop more quickly due to low mechanical inertia.
It is thus ideal for precision movements and for rapid actuation.
• Miniaturized systems encounter less thermal distortion and mechanical vibration
due to low mass.
• Miniaturized devices are particularly suited for biomedical and aerospace
applications due to their minute sizes and weight.
• Small systems have higher dimensional stability at high temperature due to
low thermal expansion.
• Smaller size of the systems means less space requirements.
This allows the packaging of more functional components in a single device.
• Less material requirements mean low cost of production and transportation.
• Ready mass production in batches.
Evolution of Microfabrication
● There is no machine tool with today’s technology can produce any device or MEMS
component of the size in the micrometer scale (or in mm sizes).
● The complex geometry of these minute MEMS components can only be produced
by various physical-chemical processes – the microfabrication techniques originally
developed for producing integrated circuit (IC) components.
gnificant technological development towards miniaturization was
initiated with the invention of transistors by three Nobel Laureates, W.
Schockley, J. Bardeen and W.H. Brattain of Bell Laboratories in 1947.
This crucial invention led to the development of the concept of
integrated circuits (IC) in 1955, and the production of the first IC three
years later by Jack Kilby of Texas Instruments.
ICs have made possible for miniaturization of many devices and
engineering systems in the last 50 years.
The invention of transistors is thus regarded as the beginning of
the 3rd Industrial Revolution in human civilization.