Wire-Free Tactile Sensing Element Based on Optical Connection

Abstract

An idea of wireless tactile sensing chip using RF connection has been proposed for realizing a soft artificial robot skin. However, it is difficult to make the RF tactile sensing element smaller than several millimeters because the energy transmission efficiency decreases as the coil size becomes smaller. In this paper we propose a wireless tactile sensing element based on optical connection. The sensing chip with 1 mm cubic shape operates with optical power, and sends optical codes of 6 stress components measured by an optical sensing method. We describe the chip design and the 6 stress sensing principle, and show experimental results of the stress sensing using a prototype of a 4 mm cubic chip. Then we estimated the required optical power for the sensing chip, and checked the operation of the digital circuit on the chip.