MEMS sensor, or Microelectro Mechanical Systems, is a multidisciplinary frontier research field developed on the basis of microelectronics technology. After more than 40 years of development, it has become one of the major scientific and technological fields that the world pays attention to.
We are mainly talking about vibration mems accelerometers. There are several types of mems accelerometers as follows: piezoresistive micro-accelerometers, capacitive micro-accelerometers, torsion-type micro-accelerometers, and tunnel-type micro-accelerometers.
The main advantages of MEMS accelerometers are: small size, light weight, low power consumption, high reliability, high sensitivity, easy integration, etc.
Status quo of MEMS accelerometers: At present, some low-end applications can be made in China, and high-end industrial applications are still quite different from those used abroad. Mainly in the frequency response range, noise ratio, resolution and so on.
The main working principle of the piezoelectric ceramic sensor is the positive piezoelectric effect. After the external force is applied, the generated charge can only be saved when the loop has an infinite input impedance, but in fact there is no such situation, so the piezoelectric Ceramic sensors can only be used to measure and sense dynamic or quasi-static stress.
The advantages of piezoelectric sensors are bandwidth, high sensitivity, high signal-to-noise ratio, simple structure, reliable operation and light weight. Piezoelectric crystals can work at a temperature above 400°C for a long time, and the instantaneous (10 millisecond) impact temperature can reach above 4000K. It can withstand high surface pressure (>150N/mm2), high stiffness, good linearity and low hysteresis. Constant sensitivity in a wide temperature range, wide frequency response range, can withstand almost unlimited load cycles, very high insulation resistance.
Comparison of MEMS accelerometers and piezoelectric ceramic accelerometers:
1. Piezoelectric ceramics have a wider frequency response range.
2. MEMS have good low frequency performance. 3. The same performance price piezoelectric ceramics are cheaper.
3. MEMS consistency is better.