A Shape Memory Alloy Actuated Microgripper with Wide Handling Ranges

• Main Authors: Che-Min Lin, 林哲民
• Other Authors: Chao-Chieh Lan
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/71097921426912673518

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === A compliant two-fingered microgripper with wide handling ranges was designed, fabricated, and demonstrated. The need for microgrippers has recently increased for varied micromanipulations such as minimally invasive surgery and biological objects harvesting. To accommodate objects of various sizes and weights, our gripper is distributedly actuated by shape memory alloy (SMA) wires so that high gripping range to gripper length ratio and mechanical advantage are achieved. A SMA actuated gripper model is presented to predict SMA strain and gripper deflection by using measurements from force sensors. Based on this model, design of the finger shape and specification of SMA wire dimension are facilitated. A fabrication technique by using CO2 laser is developed to manufacture the gripper. Two grippers with different stiffness are prototyped and their motion characteristics are demonstrated. Due to the large stress provided by SMA wires, high gripping force can be obtained. The SMA contraction force to deflect gripper and produce gripping force may be adjusted by changing the input power to SMA wire. We further investigate the feasibility of self-sensing contraction force by using SMA resistance signal. A self-powered gripper module is implemented. It can be attached on any type of manipulators for various types of micromanipulations. With the capabilities of the gripper shown, we expect that it can be applied for miniature robotic manipulations.