Voltage sensitivity of electret- and piezoelectret-accelerometers

In this paper, accelerometers utilizing the electret as well as the piezoelectret principle are presented. Such accelerometers can be operated with charge or with voltage amplifiers. Since both accelerometer types have relatively low source capacitances, their voltage sensitivity is high. This sensitivity can even be increased in case of the piezoelectret accelerometers by using stacked ferroelectret films, or, in case of the electret accelerometers by optimizing the electret voltage, the air gap thickness and other parameters.