Field-control-based nanorobotic manipulation of ions at the single atomic level is an enabling technique for such applications as in-situ prototyping and characterization for fundamental research and rapid product development of nanoscale and quantum devices such as sensors, batteries, neuromorphic devices, and neuro/brain interfaces. Taking the motion of quantum dots (QDs) manipulated by an electrostatic field steered by a probe tip on a target surface as an example, here we show a deep-learning-based approach for their global motion tracking via the individual atoms both on the surface and inside the body. Transmission electron graphs, element analysis, and crystal topology acquired from an aberration-corrected transmission electron microscope (Cs-TEM) are used to identify the positions, types, and structures of the atoms to understand their kinematics. The results show the feasibility of multi-target tracking of homogeneous atoms by their spatial structure projection, which is very encouraging for further extension to the tracking and regulation of crystalline grains, swarms of ions, ion filaments, and single ions.

Sub-structures such as micro-structured magnetic teeth fabricated with an artificial bacteria flagellum (ABF) are designed for achieving more motion modes, higher precision, and better controllability. To achieve these, a more precise model considering the non-circular cross-sectional features is setup without simplifying the structure as a helical filament with a circular cross-section as having been used in previous investigations, making it possible to include the effects of the substructures into the motion equation. Analyses and experiments verified the correctness. Besides of the geometric effects, our experimental observation also shows an anomalous step-out frequency appeared in an ABF. This asynchronous motion is attributed to the lag of magnetization with respect to the external rotating magnetic field due to the geometries and the soft-magnetic materials of the ribbons, which is different from the regular asynchronous motion solely caused by low Reynolds number of fluid to microscopic swimmers. While the lag of magnetization can be further attributed initiatively to the soft magnetic materials adopted, the feasibility to arrange the easy axis will enable many new possibilities, which is of particular interest in generating more modes for swarms such as cascade stepping out of ABFs with the same nominal overall sizes and for more precise positioning using stepping motion.