Micro-gripper for precision meso-scale assembly

Meso-scale parts are widely used in the complex miniature weapon systems. On account of a large dimension range, a variety of shapes and vulnerable structures of the meso-scale parts, the weapon systems are mainly assembled by hand, bringing poor efficiency and reliability. A challenging issue in the precision assembly of miniature weapon systems is how to safely and reliably grip the meso-scale parts in the automatic handling and assembly. A micro-gripper for gripping the sub-millimeter and millimeter scale shafts and parts is developed, including a pair of rigid and flexible gripping jaws and a precision linear motion stage. A Wheatstone bridge, which consists of strain gauges stuck on the flexible gripping jaw, is used to detect a clamping force on a part in real time. The structural parameters of flexible gripping jaw are designed optimally, and an optimal design model of gripping jaws is proposed. A simulation analysis is carried out to determine the best sticking positions of the gauges. A strain-force model for the special shape of flexible gripping jaw is derived. Grip-release experiments indicate that the micro-gripper is capable to grip the meso-scale parts stably and nondestructively.