On the desien of intelligent insoles using PVDF film

In order to measure the plantar pressure in real time, this paper developed an intelligent insole device using PVDF piezoelectric thin film. Eight sensors were used in the intelligent insoles and they are designed by double-layer PVDF piezoelectric films. The signals of the sensors was sampled and processed by the signal system composed of the preamplifier circuit and the power frequency filter circuit. The output voltage of the single- and double-layer PVDF piezoelectric thin films were tested respectively. The results showed that under the same pressure, the double-layer structure can increase the output signal of the proposed sensors and therefore the precise of the measurement could be improved. The experiment also showed the data collected was stable and reliable.