A Flexible Tactile Sensor Array Based on Pressure Conductive Rubber for Contact Force Measurement and Slip Detection

Abstract

Using INASTAMOR pressure-conductive rubber as the sensing material, we developed a flexible tactile sensor array to measure three-axis contact force and slip. The sensor array has 9 (3×3) sensing units, each consisting of three layers, i.e., a bottom electrode, conductive rubber chips, a top polydimethylsiloxane (PDMS) bump. We detailed the array’s structural design, working principle, and fabrication process. We also characterize the array’s three-axis force measurement performance. The full-scale force measurement ranges and sensitivities in x-, y-, and z-axes are characterized as 5, 5, 20 N and 0.675, 0.677, 0.251 V/N, respectively. The array is mounted on a prosthetic hand for detecting contact force and slip occurrence in grasping. Results showed that the array measures three-axis contact force and detects slippage by using discrete wavelet transformation. The tactile sensor array has potential applications in robot-hand grasping that require simultaneous slip detection and three-axis contact force measurement.