Experiments and open-loop control of multiple catalytic microrobots

Abstract

The ability to direct microrobots in the low Reynolds number regime has broad applications in engineering, biology and medicine. In contrast to externally driven robots, catalytically driven microrobots utilize chemical reactions to hyphenate all instances in solution. Controlling multiple self propelled microrobots in the same workspace has been an ongoing challenge for the field. In this paper we present a novel method for open loop control of multiple microrobots in the same workspace by combining their catalytic actuation with magnetic actuation. By using a catalytic cap to regulate the directions of motion and leveraging the inherent variations in model parameters in a collection of paramagnetic microrobots, we show how collective motion patterns can be achieved. We validate our proposed strategy in simulations using a simple kinematic model of each robot, and in experiments. Our results suggest that simultaneous steering of multiple microrobots to arbitrary locations might be controllable using sophisticated control techniques such as ensemble control.