Mutual Capacitive Flexible Tactile Sensor for 3-D Image Control

This study develops a novel mutual capacitive tactile sensor for a touch panel with shifted finger-type electrodes with high sensitivity and other benefits. This tactile sensor detects normal, shear, and pulling forces with good simultaneous visible transmittance and flexibility for the next generation of 3-D flexible portable displays. The tactile sensor is composed of polyethylene terephthalate, gold, indium tin oxide, and polydimethylsiloxane. It exhibits 75% transmittance on average in the visible region, 0.04-N force resolution, and 1.5-pF/N responsiveness. The finger-type electrode design improves sensitivity by 112%-4100%, depending on the number of fingers and shifted direction. This study conducts theoretical calculations, simulations, fabrication, and measurements.