Flexible piezoelectric tactile sensor with structural electrodes array for shape recognition system

This study provides an efficient and feasible solution to enhance the sensitivity of traditional piezoelectric tactile sensor based on introducing structural electrode upon the sensing material. A sandwich structure for flexible tactile sensor consists of top and bottom soft substrates made of Polystyrene, and in between of two soft substrates a piezoelectric thin film, PVDF, and a PDMS microstructures array are utilized as sensing material and microstructures, respectively. The experimental results showed the output voltage was linear with contact force from 10N to 0.5 N and good reliability within low frequency range 1 ~ 100 Hz. In addition, the shape recognition also can be achieved as the objective contacted with the 4 by 4 electrodes array. The effects of structural electrode on the enhancement of sensitivity were also numerically simulated by finite element method (FEM) and verified experimentally by dynamic measurement system, respectively. In general, the flexible tactile sensor developed in this study is not only applied for detecting contact force but also for the human physiology monitoring system, such as pulsation, heart rate and blood pressure, etc.