Pick-and-place nanomanipulation with three-dimensional manipulation force microscopy

Applications of the conventional atomic force microscope (AFM) succeeded in manipulating nanoparticles, nanowires or nanotubes by widely used pushing or pulling operations on a single plane. However, pick-and-place nanomanipulation is still a challenge in the air. In this paper, a modified AFM, called three-dimensional (3D) manipulation force microscope (3DMFM) was developed, aiming to achieve the pick-and-place in the air. This system mainly consists of two microcantilevers and each is quipped with a nanopositioning device and an optical lever, constructing a nanotweezer with capabilities of picking and releasing nanoobjects with force sensing. Before the 3D manipulation, one of the cantilevers is employed to position nanoobjects and locate the tip of another cantilever by image scanning, then these two cantilevers fit together as a nanotweezer to grasp, transport and place the nanoobjects with real-time force sensing. In pick-and-place experiments, silicon nanowires (SiNMs) with different diameters were manipulated and 3D nanowire crosses were achieved. 3D nanomanipulation and nanoassembly in the air could become feasible through the newly developed 3DMFM.