A tactile gripper on an optical fiber for perception and actuation

Optical fibers with integrated robotic microstructures are promising for cutting-edge applications. However, the development of microbots on a fiber system for synergistic sensing and actuation is challenging. Herein, inspired from natural Bobbit worm, we report a tactile gripper-on-a-fiber system that integrates wave spring, planar reflector with a scattering cone and a smart gripper on a single-mode fiber. The wave spring fabricated via two-photon polymerization of SU-8 can convert the applied micro-force into detectable stretching or compression, serving as a Fabry-Perot interferences sensor. Additionally, a pH responsive gripper with SU-8 frames and bovine serum albumin muscles is integrated with the wave spring, forming the tactile gripper-on-a-fiber system. As a proof-of-concept, the tactile gripper-on-a-fiber system was employed for micro-object sorting, flexible micro-block assembly, synergistic prey detection/capture, the measurement of Young’s modulus of zebrafish zygotes, and in-situ fetal movement monitoring, revealing great potential in biomedicine, precision manufacturing, minimally invasive and robotic surgery. While microrobots fabricated using two-photon polymerization have been extensively studied, integrating sensing and actuation remains a challenge. Here, the authors present a tactile gripper integrated with an optical fiber system that enables simultaneous perception and actuation.