Purdue’s microbots are designed to wander around inside your body

Luke Dormehl

“All-Terrain Microbots” sounds like it should be the name of a 1980s cartoon, accompanied by its own toy line and sugary breakfast cereal. In fact, it’s a description of the tiny microscale magnetic tumbling robots being created by researchers at Purdue University. And don’t laugh, because they may one day just save your life!

Sized 400 by 800 millionths of a meter, making them smaller than a pinhead, the dumbell-shaped microbots move by tumbling end-over-end. This unusual form of locomotion is powered by magnetic fields, and makes it possible for the microbots to travel across uneven surfaces like bumps and trenches.

“What is neat about our design is that we have come up with a way to tailor the magnetic properties of the robot that will cause it to tumble in different ways when subjected to a rotating magnetic field,” David Cappelleri, an associate professor in Purdue University’s School of Mechanical Engineering and director of Purdue’s Multi-Scale Robotics and Automation Lab, told Digital Trends. “This allows it to tumble over different types of rough, bumpy, and sticky surfaces in both dry and wet conditions. Getting a microrobot to traverse terrains like this is a challenge since surface forces like friction and stiction dominate at the microscale. By tumbling the robot over these different terrains, we avoid having to try and pull or push the robot around and have it getting stuck.”

microscale tumbling robots tumblingrobot
microscale tumbling robots tumblingrobot

Purdue University

According to Cappelleri, the robots have been specifically designed for medical use, with a hollow midsection area that could one day be used to carry a drug payload for delivery in the body. Because commercial MRI machines in hospitals already generate magnetic fields, these could be programmed to apply rotating magnetic fields able to drive the robots to their target location where the drug is to be administered.

So will the doctors of the future be telling patients to “take two all-terrain microbots and call them in the morning” then? Possibly, but there is still work to be done before we reach that point.

“Recently, we have been focused on the fundamental research side of things to obtain the best locomotion of the robots in different terrains and environmental conditions,” Cappelleri said. “Next, we plan to focus on closed-loop control of the robots as well as different payload designs. We are interested in commercializing these in the future, but we still have these and some other basic research questions to answer first.”

A paper describing the work was recently published in the journal Micromachines.