A microrobot-based technology for targeted drug delivery in the human body is being pioneered by Purdue University bioengineers. The tiny untethered devices are designed to move through uneven terrain, such as that found in the colon, by tumbling and flipping.

The miniature drug carriers are externally and wirelessly controlled and propelled with a two-degree-of-freedom rotating permanent magnet system. During in vivo experiments in the colons of live mice, the researchers used ultrasound equipment to observe in real time how well the microrobot moved around even in the presence of The P-shape and trajectory of a tumbling microrobot moving in water over an indented agarose block. U.S. penny for scale. Source: Elizabeth E. Niedert et al.tissue occlusion. Similar demonstrations were also conducted in colons removed from pigs, which have physical characteristics comparable to those of the human colon. The tumbling motion of the microrobots does not appear to pose a risk of tissue damage or puncture.

The researchers coated a microrobot with a fluorescent mock drug and place it in a vial of saline to assess its ability to carry and release a drug payload. The device successfully carried its cargo throughout the solution in a tumbling motion before the payload slowly diffused from its body an hour later.

The tumbling microrobot might also serve as a platform for advanced microsensor technologies that could in future be used to measure microbiota levels, other biological entities in the environment, or as tiny tools during minimally invasive biopsies.

The research is published in Micromachines.