A three-finger microgripper based on 3D-Assembly

Due to force scaling laws, large adhesion forces make the release of microobjects difficult. In order to achieve stable clamping, handling and reliable release of microscale components in micron scale, a three-finger microgripper was developed. The mechanical and dynamic characteristics of the microgripper are analyzed by the finite element software. The gripper is fabricated using a SOI process. Clamping operation is realized by using the electro-thermal-drive. The flat finger and the third finger are assembled into a three-dimensional structure by a micro-assembly method.Test results show the gripper obtained a displacement of 45 $\mu \mathrm{m}$ with an applied voltage of 25 V.Micro-operation experiment was made for the $70\sim 110\mu \mathrm{m}$ microspheres. The cantilever micro-clamping finger can be used to auxiliary handover the release, which can effectively overcome the adhesion between the micro ball and the finger, to achieve reliable release operation.