### 7.1.4 Summary to: 7.1 MEMS - Products and Developments

| MEMS are "Micro Electro Mechanical Systems" including also micro optics, micro fluidics and generally meaning micro systems. |  |
|  | MEMS uses Si substrates and technologies because "it is there and cheap" for the non-electronic part and because electronic components can be integrated on the same chip. |
|  | Examples of high-volume MEMS products are (Pressure) sensors. Accelerometers. Gyros "Beamer" chips (DLP) |
|  | More products are to come; MEMS is an emerging and often an enabling technology |
| Gyros are particular complex MEMS sensor products with a huge range of applications. |
|  | There must be a physical principle behind the sensor design; different approaches can be used. |
|  | One approach uses the Coriolis force causing detectable additional vibrations in an oscillator with two degrees of freedom if some rotation is experienced. |
| Many MEMS devices are either sensors or actuators. |  |
|  | Looking only at mechanical MEMS, there is a need to couple mechanical movements to electrical signals and vice verse. |
|  | Ways to do this include. Capacitive coupling Piezoelectric and piezoresisitive coupling. Thermal coupling (expansion, resistivity changes). Magnetic coupling. Optical coupling. |
|  | There is no "ideal" coupling; all methods suffer from certain problems. |
Exercise 7.1-1
All Questions to 7.1

© H. Föll (Semiconductor Technology - Script)