OptoSkin: Novel LIDAR Touch Sensors for Detection of Touch and Pressure within Wave guides

Light Detection and Ranging (LIDAR) sensors, employing direct Time-of-Flight (dTOF) measurements, are crucial for precise surface localization and are increasingly integrated into compact chip designs. These sensors have extensive use in proximity sensing in various applications. This paper presents the innovative use of LIDAR sensors for ranging within wave guides to accurately detect touch and pressure. In our OptoSkin sensors, light propagates via total internal reflection (TIR) within the wave guide. Then it is reflected back to the sensor as a result of wave guide deformation and/or scattering in the contact area, a phenomenon attributed to frustrated total internal reflection (FTIR). We have designed, simulated, and implemented different OptoSkin sensors using wave guides constructed from a flexible rod, rigid curved 3D printed resin, and planar soft silicone rubber, respectively. Each configuration is equipped with multiple LIDAR sensors, demonstrating effective localization of touch points. In addition, pressure sensing was performed on the elastic wave guides. These novel touch sensors show great potential for applications such as robotic sensor skins, which enhance tactile responsiveness and interaction.