A new capillary gripper for mini and micro parts

In the assembly of microproducts the grasping and releasing phases are key tasks. Since in the microdomain gravity becomes negligible in comparison with adhesion forces, several reliable grasping methods have been developed. On the contrary, the releasing phase is still very critical because the part tends to stick to the gripper. In this paper a novel strategy based on capillary forces both for grasping and releasing is proposed. This novel grasping-releasing strategy exploits the transition between hydrophobic and hydrophilic surfaces to change the grasping force. The paper starts from the releasing problem in microassembly, deals with the manufacturing of hydrophobic and hydrophilic surfaces and demonstrates the use of such structures to grasp and release delicate mini and microparts.