Development of flexible tactile sensors for hexapod robots

This paper describes the development of flexible based tactile array sensors based on piezoresistive rubber for use in the leg tips of hexapod robotics. The sensors are composed of a sandwich similar structure, with a piezoresistive rubber used as the middle layer and flexPCB electrodes on the upper and lower part of the rubber. To address a wider range of tactile stimuli, namely the dynamic tactile stimuli, a piezoelectric thin film sensor based on polyvinylidene fluoride(PVDF) is embedded into the leg tip mould. Both piezoresistive array and piezoelectric types of sensors are investigated in terms of characteristic and signal conditioning methods are proposed for both layers. Experimental validation addresses object texture recognition with high classification results (over 85%) based on active exploration and learning the signals captured by the piezoelectric layer. A simple method for slip detection based on learning the slip signal from the piezoelectric layer is also investigated.