Micro-nanorobotic manipulation system for single cell positioning. (a) Scanning electron micrographs of a microgripper . (b) Five electromagnetic coils are mounted on an optical microscope to actuate the magnetic robot in the center . (c) Microbeads dancing controlled by the optical tweezers . (d) Cell positioning by dielectrophoresis (DEP) chip . (e) Schematic drawing of the optoelectronic tweezers (OETs) .