Microparticle manipulation using multiple untethered magnetic micro-robots on an electrostatic surface

This work presents the control of multiple untethered rectilinear magnetic micro-robots (Mag-¿Bots) with dimensions 250 × 130 × 100 ¿m³ actuated by pulsed external magnetic fields, which translate by induced stick-slip motion at speeds of up to 4 mm/s immersed in silicone oil. Multiple Mag-¿Bot control is enabled by employing an array of individually addressable electrostatic surfaces to selectively anchor individual Mag-¿Bots. Coupled parallel and uncoupled serial motion of multiple robots is demonstrated, and they can combine to form an assembly that is also capable of motion. Manipulation of 230 ¿m diameter microspheres is also demonstrated cooperatively by two Mag-¿Bots in a fluid environment, and is enhanced when the two Mag-¿Bots are combined. An analysis of the electrostatic anchoring forces and the forces relevant to manipulation is discussed.