Abstract:
The sense of touch is fundamental for a one-to-one mapping between the environment and 1 a robot that physically interacts with the environment. Herein, we describe a tactile fingertip design 2 that can robustly detect interaction forces given data collected from a camera. This design is based 3 on the photoelastic effect observed in silicone matter. Under the force applied to the silicone rubber, 4 owing to the stress-induced birefringence, the light propagating within the silicone rubber is subjected 5 to the angular phase shift, where the latter is proportional to the increase of the image brightness 6 in the camera frames. We present the calibration and test results of the photoelastic sensor design 7 on a bench using a robot arm and with a certified industrial force torque sensor. We also discuss the 8applications of this sensor design and its potential relationship with human mechano-transduction 9 receptors. We achieved a force sensing range of up to 8 N with a force resolution of around 0.5 N. 10 The photoelastic tactile fingertip is suitable for robot grasping and might lead to further progress in 11 robust tactile sensing.
