Designing non-electronic biological machines has been a riddle that scientists at the interface of biology and engineering have struggled to solve. The walking bio-bots demonstrate the Illinois team’s ability to forward-engineer functional machines using only hydrogel, heart cells and a 3-D printer.

With an altered design, the bio-bots could be customized for specific applications in medicine, energy or the environment. The key to the bio-bots’ locomotion is asymmetry. Resembling a tiny springboard, each bot has one long, thin leg resting on a stout supporting leg. The thin leg is covered with rat cardiac cells. When the heart cells beat, the long leg pulses, propelling the bio-bot forward.

The team uses a 3-D printing method common in rapid prototyping to make the main body of the bot from hydrogel, a soft gelatin-like polymer. This approach allowed the researchers to explore various conformations and adjust their design for maximum speed. The ease of quickly altering design also will allow them to build and test other configurations with an eye toward potential applications.

For example, the team envisions the bio-bots being used for drug screening or chemical analysis, since the bots’ motion can indicate how the cells are responding to the environment. By integrating cells that respond to certain stimuli, such as chemical gradients, the bio-bots could be used as sensors.

Next, the team will work to enhance control and function, such as integrating neurons to direct motion or cells that respond to light. They are also working on creating robots of different shapes, different numbers of legs, and robots that could climb slopes or steps.

This story is reprinted from material from University of Illinois, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.