An accelerometer based on thermoformed piezoelectrets with open-tubular channels

Ferro- or piezoelectrets (especially thermoformed multilayer systems), developed at the beginning of 2000, exhibit flexibility and high piezoelectricity as their major properties. These materials have led to significant technological advances in several applications, including sensors and transducers, such as underwater ultrasound and accelerometers. This paper introduces a new approach for the production of an accelerometer. A piezoelectret prepared with an open tubular-channel structure was employed as a mass-sensor. The accelerometer was built in an aluminum housing with an encapsulated mass and tested in a standard shaker, which produced vibrations in up to 4.5 kHz frequency range. The results show a linear behavior from 1.1 kHz to 4 kHz, which is in good agreement with a commercial accelerometer.