Design, Fabrication and Vision Based Operational Analysis of Novel Shape Memory Alloy Micro Grippers

Object grip, grasp, hold and place type of tasks incorporate specific engineering design concepts. Considering such principals, eight gripper mechanisms were designed and produced which can be classified as micro grippers due to their small workspace, precise grasping and holding abilities. Common characteristics of all the designs are that, without using any electric motor, the open-close operation is by virtue of shape-memory alloys. Each gripper is designed for different purposes with different operational principles of which four were initially open and the other four were initially closed configurations. Parametric studies were performed by changing the duty cycle and frequency of pulse width modulation using a signal generator followed by measurement of gripper jaw clearance, open-close period, average open-close velocities, gripping force, holding and lifting abilities of the designed gripper mechanisms. Jaw displacement and velocity parameters were computed by image processing of video records captured during the operation of the gripper mechanisms.