Two-dimensional vision-based autonomous microparticle manipulation using a nanoprobe

Autonomous micromanipulation has been an emerging interest in constructing and assembling micro-objects. Manual assembly and manipulation of small-scale objects through teleoperation is possible; however, autonomy is necessary for large-volume manipulation and manufacturing. In this study, we discuss a two-dimensional autonomous manipulation system, which is based on an optical microscope and a nanoprobe. We demonstrate the manipulation of polystyrene and silica microspheres, which are detected through image processing using the generalized Hough transform. Using an atomic force microscope nanoprobe as an end-effector, microspheres are autonomously pushed to a user-defined configuration. Furthermore, we demonstrate motion planning in micromanipulation by using the Wavefront expansion algorithm, which is necessary in manipulating microspheres without colliding into obstacles. In experiments, we successfully demonstrate the automatic arrangement of 4.5 μm polystyrene and 5 μm silica microspheres into user-defined patterns with an average precision of around 0.5 μm, which is limited by the microscope imaging resolution. This autonomous microparticle arrangement system could be applied to fabricate mold templates for micro/nanoprinting and prototyping micro/nanodevices.