Free manipulation system for nanorobot cluster based on complicated multi-coil electromagnetic actuator.

Chemotherapy is an important method in the field of cancer treatment and often follows surgery and/or radiotherapy to remove as many tumor cells as possible. In particular, among the chemotherapy methods, treatment using electromagnetic-based actuation systems is considered an effective method owing to the remote control of nanorobots. The existing electromagnetic-based actuation systems, however, have certain disadvantages such as the lack of degrees of freedom and the difficulty of manipulating large numbers of nanorobots (i.e., nanorobot clusters). Herein, we report that nanorobot clusters can be manipulated with high degrees of freedom through a simple parameter alpha that easily controls the gradient of the magnetic field of a multi-coil electromagnetic actuation system. The simulation results show that the gradient of the magnetic field is controlled using an introduced parameter, alpha, and the corresponding velocity is also controlled. Not only the velocity of the nanorobot cluster but also the unrestricted spatial control is enabled in two- and three-dimensions. We believe this study highlights an efficient method of electromagnetic control for cluster-based drug delivery.