Active-Matrix Tactile Sensor Array Based on the Monolithic Integration of Pvdf and Dual-Gate Transistors

Demonstrated presently is a tactile sensor array consisting of monolithically integrated polyvinylidene fluoride (PVDF) piezoelectric sensing film and active-matrix circuits based on metal-oxide thin-film transistors (TFTs). Amorphous indium-tin-zinc oxide is chosen as the semiconductor to realize TFTs intrinsically operating in the depletion mode, thus allowing the implementation of a higher-gain pixel amplifier. A dual-gate TFT with an extended top gate is deployed to couple the raw sensor signal to the amplifier and the active portion of the PVDF film is made to stand above all other features to facilitate sensing of a distributed force load. The feasibility of the technology has been verified using an 8×8 active-matrix sensor array.