Design and development of a novel micro-clasp gripper for micromanipulation of complex-shaped objects

This paper presents the design and development of a novel tool, called the micro-clasp gripper, for accomplishing firm and stable gripping and manipulation of complex-shaped micro-scale objects in any orientation using a single rectilinear actuator. The micro-clasp gripper is a compliant mechanism comprised of an endeffector with a closed-loop boundary that can be folded and unfolded in a plane by the action of the rectilinear actuator. Upon actuation, the endeffector of the micro-clasp gripper clasps an object by first encircling the object, and then, folding in on the object to accomplish multi-point contact with the object. This clasping of the micro-object with multi-point contact ensures a stable grip on the object regardless of its shape and initial orientation, even in presence of ambient disturbances the transport of the object or complex micromanipulation and microassembly tasks. The design of the micro-clasp gripper is obtained through a systematic modeling and topology optimization techniques, and a proof-of-principle device is microfabricated using conventional micromachining techniques. The device design is validated through experiment-model correlation studies on the input-output characteristic of the micromachined prototype, and practical feasibility of the clasping functionality of the gripper is demonstrated through experiments involving grasping and repositioning of irregularly shaped micro-particles on a glass substrate.