Design of a Microforce Sensing Gripper for Micro/Nano Manipulation Based on Optical Fiber Sensing

In the micro/nano manipulation system, grippers with high precesion force feedback is of great importance for the precise manipulation of small samples, especially those fragile ones such as cell. This paper proposes a microgripper with high precision force feedback, which is composed of two microforce sensors and a stick-slip platform. The sensors are all based based on silicon cantilever beams and used single-mode optical fibers with fiber Bragg gratings as the sensing elements. Factors affecting the maximum reflectance as well as the maximum reflected wavelength are all analyzed theoretically. The force feedback accuracy of the gripper is also tested. The designed gripper can realize the force feedback with 5 µN precision. The experimental results of clampping of a zebrafish embryo shows that the designed gripper can realize the real-time force sensing of micro-Newton force.