Tumbling Magnetic Microrobots for Biomedical Applications

This paper presents a magnetic microrobot that demonstrates the ability to travel through wet conditions inside a murine colon. Under the influence of an external rotating magnetic field, it tumbles end-over-end to propel itself forward. The microrobot's real-time position can be accurately tracked using ultrasound imaging to help guide it to a desired target location. Diffusion tests were conducted and show that the microrobot releases a fluorescein payload over a two hour time period when it is applied as a coating. Cytotoxicity tests demonstrated that the microrobot's SU-8 body doped with magnetic NdFeB particles is also biocompatible with murine fibroblasts. The microrobot's capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.