Hybrid Additive Manufacturing of 3D Compliant Tactile Sensors

Abstract

A resistance based conformal, compliant multi-layer tactile sensor was designed and built layer by layer using a hybrid manufacturing process. A highly stretchable, photocurable, piezoresistive sensing material was deposited on a conformal, soft molded structure using a direct printing device. The principle of the sensor is based on detecting the changes in resistance as it is deformed. The fabricated tactile sensor consists of two layers of sensing elements within the 3D skin structure where the sensing elements in the top layer are orthogonally placed atop the bottom layer. Due to the multiple layers of wires, the sensor can potentially detect various external forces/motions in two and/or three dimensions. Piezoresistivity and conductivity was introduced into the nonconductive stretchable prepolymer through dispersion of multi-walled carbon nanotubes (MWNTs). Experiments were performed to characterize the ability of the sensor to detect the location that forces were applied to the surface. Finally, it is expected that the developed conformal tactile sensor using the hybrid manufacturing method and materials could be used for various robotics and electronics applications.