Development of a unique sensor using piezoelectric plate

In this paper, a unique sensor is developed by wireless electric field transmission method. The sensor is a piezoelectric plate made of lead zirconate titanate (PZT) ceramic material with separated input and output parts. The sensor uses the PZT plate to detect electric field and attenuated output voltage signal wirelessly. The electric field is generated by an AC voltage connected to two metal electrodes mounted on a plastic plate with a tunable separation. The PZT plate is aligned along the central axis of the gap between two metal electrodes. The operation principle is based on the coupling of an electromagnetic wave and mechanical resonance vibration. When an electric field penetrates the piezoelectric plate, an attenuated voltage signal was obtained from output section of the piezoelectric plate. The sensor has a very stable output signal, and a sensitivity which can be tuned by the size of input and output sections, electric field and operating vibration modes.