Piezoelectric polymer tactile sensor arrays for robotics

Six piezoelectric polymer tactile sensor arrays for robotics have been designed, fabricated, and evaluated for piezoelectric activity and tactile sensing. Two of the arrays were thermally poled. Each consisted of a planar 5*5 arrangement of identical (3 mm*3 mm) discrete sensors made of polyvinylidene fluoride with Al electrodes. PVDF provided a pressure sensing capability. The sensor´s spatial configuration provides information for discerning an object´s shape. The PVDF film was evaluated for two film thicknesses (25 and 40 mu m) and for two versions (unmetallized and vendor-metallized). Two electrode fabrication processes were developed to accommodate the inherent chemical and temperature limitations of the PVDF film. Four array configurations which performed significantly better than the others were square-pad designs that used the 40- mu m thick PVDF film. Two sensor-element spacings (500 and 750 mu m) and electrode-fabrication processes (evaporation and photolithographic) were represented equally in the fabrication of this set.<>