A New Compliant Microgripper with Integrated Position and Force Sensing

This paper presents the design and development of a new compliant microgripper with integrated position and force sensing capabilities. The gripper mechanism is devised and verified by performing finite element analysis (FEA), and it is fabricated using the wire-electrical discharge machining (EDM) process. The gripper is driven with a piezoelectric stack actuator (PSA) and the position and force feedback are realized via two groups of strain gauges, which provide the (2 sigma) resolution of 0.22 mu m and 1.02 mN, respectively. With the calibrated sensors, the static and dynamic performances of the gripper are characterized. Moreover, a position and force switching control scheme is implemented to demonstrate the effectiveness of the microgripper system for grasp-hold-release operation of a copper wire of 300-mu m diameter. The developed microgripper system is capable of conducting microassembly of micro objects along with both position and grasping force regulated.