Miniaturized Walking Biological Machines Developed in Illinois

Researchers at the University of Illinois have come up with a remarkable creation-- biocompatible miniature bio bots.

With the ability to walk by themselves, these 7 millimeters long bio bots demonstrate the Illinois team's ability to forward-engineer functional machines using only hydrogel, heart cells and a 3-D printer.

The research was led by University of Illinois professor Rashid Bashir. He believes that these bio bots can be used for specific applications in medicine, energy or the environment once a little alteration is made to the design.

"The idea is that, by being able to design with biological structures, we can harness the power of cells and nature to address challenges facing society," said Bashir, an Abel Bliss professor of engineering. "As engineers, we've always built things with hard materials, materials that are very predictable. Yet there are a lot of applications where nature solves a problem in such an elegant way. Can we replicate some of that if we can understand how to put things together with cells?"

Similar to a tiny springboard, each bot has a long thin leg that rests on a stout supporting leg. The locomotion of the bio bots is asymmetrical. The researchers covered the bot's thin legs with rat cardiac cells. The beating of the heart cells propels the bio-bot forward.

The main body of the bot was made using 3-D printing method. It was manufactured from hydrogel, a soft gelatin-like polymer. This approach allowed the researchers to explore various conformations and adjust their design for maximum speed.

"Our goal is to see if we can get this thing to move towards chemical gradients, so we could eventually design something that can look for a specific toxin and then try to neutralize it," said Bashir. "Now you can think about a sensor that's moving and constantly sampling and doing something useful, in medicine and the environment. The applications could be many, depending on what cell types we use and where we want to go with it," he added.

The team next plans to enhance control and function. They are also working on creating robots of different shapes, different numbers of legs and robots that can climb slopes or steps.

"The idea here is that you can do it by forward-engineering," said Bashir, who is also director of the Micro and Nanotechnology Laboratory. "We have the design rules to make these millimeter-scale shapes and different physical architectures, which hasn't been done with this level of control. What we want to do now is add more functionality to it."

"I think we are just beginning to scratch the surface in this regard," said graduate student Vincent Chan, first author of the paper. "That is what's so exciting about this technology -- to be able to exploit some of nature's unique capabilities and utilize it for other beneficial purposes or functions."

The results were published in the journal Scientific Reports.