Object imaging with a multiplexed piezoelectric polymer tactile sensor

Abstract

A two-dimensional, electrically multiplexed robotic tactile sensor fabricated by coupling a piezoelectric polyvinylidene fluoride (PVDF) polymeric film to a monolithic silicon integrated circuit (IC) is discussed. The integrated circuit incorporates 25 sensor electrodes arranged in a symmetrical 5*5 matrix. Each electrode occupies a 600- mu m by 600- mu m square area. A 25- mu m-thick PVDF film was attached to the electrode array with a nonconductive adhesive. The response of the tactile sensor is essentially linear for loads spanning 0.8 to 60 grams of force (GMF). The response bandwidth is 33 Hz, the hysteresis level is very small, and taxel crosstalk is not a significant problem. A precharge bias scheme has been implemented to stabilize the pre- and post-load sensor response. A simple tactile object image measurement process was evaluated to recognize the shapes of circular, rectangular, toroidal, and hexagonal loads.<>