Development of static load sensor utilizing both direct and inverse piezoelectric effect of piezoelectric element

Abstract

It's possible to measure static load using piezoelectric ceramics by sticking 2 pieces of identical ceramics together. When one of the ceramics is oscillated at its resonant frequency, the other ceramics generates voltage by following up to the motion of the actuator ceramics. The vibration of the body is suppressed due to the impressed load, and then the sensor voltage drops according to the magnitude of the load. Vibration analysis proved that the configuration of the vibration of the sensor body is simple 1^st mode bending of a thin circular plate. It's also turned out that the characteristics of the sensor voltage are dominated not by the magnitude of the load but by the contact area of the load with the ceramics. Therefore, introducing the cushion material, which alters the contact area according to the magnitude of the load, will improve the sensitivity and the linearity of the sensor voltage to the load.