Sheet Type Impact Force Sensor by the Use of Piezoelectric Film

Two kinds of sheet type impact force sensor are developed : frictionless impact sensor and multi-contact impact sensor. Sensor structure consists of a main body and cover member. Main body of the sensor is made from piezoelectric film (PVDF) and silicon rubber. Frictionless impact sensor is wrapped by a flexible cover member. Oil layer is placed in between the main body and cover member. Multi-contact impact sensor has solid cover plates on both surfaces of the main body. The solid cover plates play a role to transmit impact force to main body by a mechanism of multi-contact loading. The performance of the impact sensor is examined through experiment by applying several impact forces using hand hammer, hand-grip and screw driver head pressing. A good linear relationships between applied impact force and sensor output are observed for both sensors.