Simultaneous control of spherical microrobots using catalytic and magnetic actuation

The ability to steer multiple microrobots in different directions in the same workplace has been an ongoing challenge for the field. In this paper we present a novel method of controlling multiple microrobots in the same workplace by combining their magnetic actuation with catalytic motion. We achieve motion differentiation through the use of paramagnetic microrobots which assume different magnetizations in the same field. This is combined with a catalytic cap which regulates the direction of motion of the microrobot. Independent motion and steering control is demonstrated for groups of one, two and three microrobots. Furthermore, the robustness of the system is demonstrated by attachment and detachment of two microrobots using a common magnetic field. This proposed method could be used for wide ranging applications in the fields of engineering, biology and medicine. Especially in the field of cargo and drug delivery, the ability to steer individual particles to user defined locations is very important and, in this paper, we demonstrate that an individual microrobot can be reliably steered to a user defined location.