Development of Micro Gripper for Microfactory Using Two-Way Shape Memory Alloy

To develop an automated microfactory system, a micro gripper to handle various-shaped works with large gripping force should be required. In this paper, a micro gripper using two-way shape memory alloy (TSMA) is designed. As the result, 28 [mm] size gripper to handle works of 5 [mm] diameter with more than 3 [N] gripping force is prototyped using TSMA plate of 0.45 [mm] thickness, 10 [mm] width, and 35 [mm] length. Optimization of TSMA configuration shows a possibility of an improved gripper design of 22 [mm] size and 20 [N] gripping force using currently available TSMA. Also, scale analysis shows the gripping force is in proportion to the square of scale parameter ε, and thus it indicates the gripper design of 1 [mm] size and 59 [mN] gripping force should be possible.