A Polymer-Based Flexible Tactile Sensor for Normal and Shear Load Detection

This paper presents a novel flexible tactile sensor, which can detect shear as well as normal load, simultaneously. The proposed sensor uses easy fabrication steps and low cost materials (i.e. Polymers, Copper and Nickel). This metal/polymer multilayer structure enables it to withstand overpressure, and to be mechanically flexible so that it can be attached to an arbitrary surface such as the body of house-helper robots as a sensitive skin. The sensing principle is embedding strain gauges at the centre of ductile polymer substrate. The unit cell characteristics against normal and shear load are evaluated. At normal load test, the sensitivity (8 µ V/kPa) is less than a silicon diaphragm based tactile sensor but the operational range is much wider (0 to 4 N). And the shear load can be detected by the voltage drop across one strain gauge is increasing while across the other is decreasing. A ring-shaped tactile images has been successfully captured by 8×8 flexible tactile sensor.