(Invited) Post-CMOS Compatible Silicon MEMS Nano-Tactile Sensor for Touch Feeling Discrimination of Materials

Abstract

Based on silicon post-CMOS compatible process, we have realized high performance silicon MEMS tactile sensor called “Nano-tactile sensor”, which is comparable to the performance of fingertip sense of touch. In this tactile sensor device, all the mechanical structures are made from single crystalline silicon which is the active layer of SOI wafers. No elastomer/polymer structures are used in the mechanical sensing structure, and softness and elasticity necessary to tactile sensing are realized by silicon micro mechanical structures. In the latest version of our tactile sensors, six contactors with fingerprint-like shape are integrated at a pitch of 500µm to get high spatial resolution tactile images. Each fingerprint-like contactor reproduces vertical motion (by micro roughness) and horizontal motion (by frictional force) of a fingerprint closely under sweeping motion of fingertip in measurement. The performances are enough high to analyze surface touch feelings of “Hair surface condition”, “Skin condition”, and “Touch feeling of various papers and clothes” like human fingertip. Combination of high-resolution tactile sensor and deep neural network is a strong approach to reproduce human fingertip sensation by state-of-the-art device electron device technology.