Application of High-Photoelasticity Polyurethane to Tactile Sensor for Robot Hands.

We developed a tactile sensor for robot hands that can measure normal force (F Z ) and tangential forces (F X and F Y ) using photoelasticity. This tactile sensor has three photodiodes and three light-emitting diode (LED) white light sources. The sensor is composed of multiple elastic materials, including a highly photoelastic polyurethane sheet, and the sensor can detect both normal and tangential forces through the deformation, ben sding, twisting, and extension of the elastic materials. The force detection utilizes the light scattering resulting from birefringence.