Three-dimensional automated micromanipulation using a nanotip gripper with multi-feedback

In this paper, three-dimensional (3D) automated micromanipulation at the scale of several micrometers using a nanotip gripper with multi-feedback is presented. The gripper is constructed from protrudent tips of two individually actuated atomic force microscope cantilevers; each cantilever is equipped with an optical lever. A manipulation protocol allows these two cantilevers to form a gripper to pick and place micro-objects without adhesive-force obstacles in air. For grasping, amplitude feedback from the dithering cantilever with its normal resonant frequency is used to search a grasping point by laterally scanning the side of the microspheres. Real-time force sensing is available for monitoring the whole pick-and-place process with pick-up, transport and release steps. For trajectory planning, an algorithm based on the shortest path solution is used to obtained 3D micropatterns with high levels of efficiency. In experiments, 20 microspheres with diameters from 3 μm to 4 μm were manipulated and 5 3D micropyramids with two layers were built. Three-dimensional micromanipulation and microassembly at the scale of several microns to the submicron scale could become feasible through the newly developed 3D micromanipulation system with a nanotip gripper. (Some figures in this article are in colour only in the electronic version)