Design, Fabrication, and Wireless Control of 3D-microprinted Robots for Biomedical Applications

Abstract

This paper dealt with the design, fabrication, control, and evaluation of an untethered robot for biomedical applications. Helical tubular microstructures were first printed using a two-photon lithography (2PP) system, which can precisely print 3D microstructures at a nanoscale resolution. The microstructures were then masked with dopamine using in situ polymerization to facilitate magnetic nanoparticles (MNPs) and anticancer drug deposition onto their surfaces to make the microrobots with therapeutic functions. The MNP deposition allowed the wireless manipulation of the microrobots using an external magnetic actuating (EMA) system. While the addition of an anticancer drug could be used to release to the cancer area to which the microrobots were controlled. The printed microrobots had a length of 465 μm and an outer diameter (including helical wings) of 185 μm. Under the external magnetic field, the microrobots could move using helical motion with an average velocity of as high as 126 μm/s. Moreover, they could be controlled following various predefined trajectories. Finally, the therapeutic functions of the microrobots were tested by incubating the microrobots with human-origin cancer cells. The result showed that the microrobots could effectively kill the cells following a dose-dependent manner in 24 h. Thus this work proposes an innovative approach to prepare and apply a wirelessly manipulated microrobot for active targeting and treatment of cancerous cells.