Micro Electro Mechanical Systems (MEMS) is the process of producing and combining miniaturized mechanical elements, sensors, actuators and electronics. MEMS make technology possible by developing smart products, increasing the computational ability of micro electronics with the quality and control capabilities of micro sensors and micro actuators and increase space of importance in design and application. MEMS are called “Micromachines” in Japan and “Microsystem Technology” in Europe. Working of Shoe based sensors with MEMS technology: This operation works on chip scale inertial sensors. This sensor provides the power and size requirements for portable applications. Due to inherent
bias drift and noise in sensor, error is caused in the rapid growth of position. A RF velocity sensor is used to limit this error growth. If the shoe touches the ground, it is detected by RF velocity sensor. Three different sensors are implanted in shoe. RF terrain relative velocity sensor is placed at the heel of shoe that is used for position reckon from the accelerometers in the inertial measurement unit (IMU). Magnometers in IMU provides the heading reckon from the gyroscope. The location of moving one shoe can be found with the shoe relative sensors with respect to stationary shoe. Applications using MEMS technology: Biotechnology: With the help of MEMS technology new discoveries in science and engineering are developed. Some of them are Polymerase Chain Reaction (PCR) Microsystems for amplification and identification of DNA, micro machined Scanning Tunneling Microscope (STMs), biochips for finding the hazardous chemical and biological agents. Communications: Electrical components such as inductors and tunable capacitors can be developed by comparing integrated counterparts. With the integration of such components, power consumption cost will be reduced and the performance of communication circuits will also improve. The demonstrated samples of various micro wave switches have higher quality factors than the previously made switches. Accelerometers: Conventional accelerometers are quickly replaced by MEMS accelerometers for crash air bag deployment system in automobile. The conventional
accelerometers uses bulky accelerometers made of discrete components placed in the front
of the car with separate electronics near the air bag. This conventional accelerometer costs over $50 per automobile. MEMS have made it possible by integrating the accelerometer with a single silicon chip which costs about $5 to $10. These MEMS accelerometers are smaller, lighter, and more reliable. Advantages of using MEMS technology:
- Low cost
- No charge amplifiers are required.
- Useful in the field of defense.
- Useful in health applications of many machines.
- More expensive because of high effective sensors.
- Lack in Industrial hardened packages
- Compact in size.
- Shock resistant.
- Inexpensive when according to IC batch fabrication.
- Low interference.
- Sampling size is large.
MEMS based sensors are very important component in automotive electronics, medical applications, and smart portable electronics such as cell phones, hard disk drives and wireless devices. They are now becoming the most used technology in crash detection in car air bag systems. They are also becoming the useful component in everything from cell phones to inkjet cartridges. Every major market are now holding this technology closely in their arms.