Novel high resolution tactile robotic fingertips

This paper describes a novel robotic fingertip based on piezoresistive rubber that can sense pressure tactile stimuli with a high spatial resolution over curved surfaces. The working principle is based on a three-layer sandwich structure (conductive electrodes on top and bottom and piezoresistive rubber in the middle). For the conductive layers we use ring patterns of silver epoxy and flex PCB electrode arrays. The proposed sensorised fingertip has 60 sensitive regions (taxels) arranged in 5 rings and 12 columns that have a smooth pressure to resistance characteristic. Using the sensor with specialized data acquisition electronics that acquire 500 frames per second provides rich information regarding contact force, shape and angle for bio-inspired robotic fingertips. Furthermore, a model of estimating the force of contact based on values of the cells is proposed.