Finger-Skin-Inspired Flexible Optical Sensor For Force Sensing And Slip Detection In Robotic Grasping

The finger skin of human plays a key role in amplifying and transferring tactile signals to sensory receptors, and it provides design guidelines for next-generation flexible tactile sensors. To enable robotic applications such as dexterous manipulation and tactile feedback, the functions of force sensing and slip detection are crucial for flexible tactile sensors. Here, a finger-skin inspired flexible optical (FIFO) sensor based on optical microfiber is reported, and this sensor has fingerprint-like surface with parallel ridges and resin/polydimethylsiloxane multilayer structure with different stiffness, mimicking the structural characteristics of human finger skin. With these design features, the sensor is capable of measuring force with high durability and detecting slip with high sensitivity and short response time. Time-resolved response curve and its wavelet transform provide useful information related to grasping and slipping when the sensor is in contact with objects with different shapes and materials. As a proof-of-concept demonstration, the sensor directly attached onto a robotic gripper is capable of measuring grasping force and monitoring object slippage during manipulation tasks, indicating its potential applications in advanced robotics.