Performance Evaluation of a MEMS Microgripper with Double-Sided Capacitive Sensing for High-Precision Micromanipulation

This work presents a novel MEMS-based microgripper integrating electrostatic actuation and capacitive motion sensing, both achieved through interdigitated rotary comb structures. The device features curved flexure hinges for tip motion and ten pairs of electrostatic comb drive actuators for independently controllable tip displacement on both sides within a 130 μm × 75 μm workspace. Four pairs of double-sided rotary combs provide real-time position feedback of both tips, achieving a sensitivity of 5.2 fF/μm. Finite Element Method (FEM) simulations confirm a maximum tip displacement of 65 μm under 12 V, and a torque generation of up to 3.9 × 10−10 Nm. Mechanical stress analysis shows that the design remains well within the structural limits of silicon, ensuring long-term reliability. The proposed device enables closed-loop control of jaw position, offering a compact and robust solution for high-precision micromanipulation tasks, such as single-cell stimulation, microsurgery, and lab-on-chip biological analyses.