Development of a Compliant-Based Microgripper for Microassembly

Micro-scaled parts with dimension below 1 mm need to be manipulated with high precision and consistency in order to guarantee successful microassembly process. Often these requirements are difficult to be achieved mainly due to the constraints imposed by the grasping mechanism which will affect the accuracy of the manipulation. Furthermore, the object´s texture and fragility imply that small perturbation by the grasping mechanism can result in substantial damage to the object and downgrading its geometry, shape, and quality. Conventional grippers based on rigid hinges are not capable to meet the demand of high precision manipulation and control of micro objects due to prevalent backlash and coulomb friction problems inherited within their joints. An effective way to address these problems is by introducing flexure based joints which will produce fully-monolithic grasping mechanism. This paper provides a rigorous approach to develop a compliant-based microgripper for performing high precision manipulation of micro-objects. A combination of pseudo rigid body model (PRBM) and finite element analysis (FEA) has proven to expedite the prototyping procedure which effectively reduces the cost and modeling time. An electro discharge machining (EDM) technique was utilized for the fabrication of the device. Series of experimental studies were conducted for performance verification and the results were compared with the computational analysis results. A high displacement amplification and maximum stroke of 100 mum can be achieved.