A Vacuum Microgripper with Integrated 3D Force Sensing Capabilities via Dual-Material Flexure Hinges

Accurate force sensing capability is essential for microgrippers to achieve reliable and compliant manipulation of microcomponents in advanced manufacturing applications. To address the current lack of multi-axis force sensing capability in vacuum microgrippers for micromanipulation tasks, we developed a three-dimensional (3D) force-sensing vacuum microgripper incorporating a dual-material flexure hinge that maintains high stiffness and sensitivity while overcoming the traditional stiffness reduction limitation. The dual-material flexure hinge, as the fundamental sensing element, exhibits enhanced surface strain under loading conditions due to the interfacial stress interaction between the photosensitive resin and low-stiffness silicone rubber. It demonstrates 1.79-fold greater sensitivity and 2.39-fold higher stiffness compared to conventional rectangular hinges of equivalent dimensions. The developed vacuum microgripper achieves millinewton force measurement resolution while preserving the structural stiffness essential for reliable micromanipulation. Sensing performance assessments and micropart manipulation experiments demonstrate the superior performance of the proposed vacuum microgripper. This study presents a novel design strategy for developing vacuum microgrippers with enhanced 3D force sensing capabilities.