Flexible vacuum gripper with autonomous switchable valves

Abstract

A flexible vacuum gripper having miniature arrayed valves is proposed; the valves are normally closed, and opened when contacted with object. Since the gripper is made of flexible polymer material and only the valves contacted with the object are opened to suck the surface, this gripper can hold a free-form surface such as having steps, curvatures, etc. Namely, the valve is autonomously switchable between open and close states. As the valve becomes small, the gripper can cope with higher step and higher curvature. We fabricate this gripper using Micro Electro Mechanical Systems (MEMS) technology; this technology makes it possible to fabricating many elements with micrometer order high precision by batch processing. Two types of gripper were fabricated; one is a large-scale gripper for verifying the working principle, another is a miniature gripper based on MEMS. The absorbed weights of the large-scale and miniature grippers were 19.6 N (2 kgf) and 120 mN (12 gf), respectively.