Silicon Three-axial Tactile Sensor

Abstract

A novel three-axial tactile sensor based on the differential capacitive principle is presented. The sensor is fabricated using IC processing and bulk micromachining technology. Normal and shear forces are detected by capacitor arrays under force mesas. Experimental devices show sensitivities of 0.13 pF/grarn to normal forces, and 0.32 pF/gram to shear forces in a force range of 0-1 gram. The spatial resolution is 2.2 mm, and the maximum dynamic response frequency is 162 Hz. The force range and sensitivity can be adjusted by changing the membrane thickness. A dynamic load range of more than 100 can be obtained using a detection circuit with a resolution of 10 fF.