A Novel Three-Axial Force Tactile Sensor Based on the Fringing Effect of Electric Field

A novel flexible three-axial tactile sensor, which is composed of four interdigital capacitors, is presented in this paper. The operation of the sensor is based on the measurement of a load-induced capacitance change. For the configuration of the electrodes, four sensing electrodes and a public electrode are in the same plane, which is based on the fringing effect of the electric field. There are no floating electrodes which are beneficial to flexibility. The dielectric layer consists of air gap and polydimethylsiloxane (PDMS), and the equivalent dielectric constant of the dielectric layer will be changed when the sensor is under external force, which causes the capacitance change. Different from the existing fringing effect tactile sensor, interdigital electrodes are adopted here to enhance the sensitivity and stability of the sensor. Finite element simulation and experimental results show that there is a great enhancement in sensitivity and stability.