A ROBOTIC SYSTEM FOR PERFORMING SUBMILLIMETER GRASPING AND MANIPULATION TASKS

A robotic system for performing sub-millimetre grasping and manipulation tasks has been designed and tested. The system consists of a two-fingered gripper attached to a six-degrees-of-freedom robotic manipulator. Features of the system include: (1) the structure of the manipulator contains six spring-tensioned tendons - this makes the manipulator easy to construct and allows it to collapse in a reversible manner when overloaded, (2) step-motor driven winches adjust the tendon lengths and through them control the position and orientation of the gripper, (3) the gripper is actuated by a shape memory alloy actuator and employs an optical sensor to measure finger separation. The prototype version of this manipulator can perform a minimum movement of less than 0.05 mm and manipulates objects in the size range 2 mm to 0.2 mm. The design of the robotic manipulator and gripper afford plenty of scope for further miniaturisation. With the recent increased interest that has been shown in microrobotics there will be a need for robotic systems capable of assembling and manipulating microcomponents. The prototype robotic system described in this paper could, with further development and refinement, form part of a microrobot assembly system.