Biological Machines In The Making: 3D Printed Bio-Bots Combine Biology With Electricity
Engineers from the bioengineering department at the University of Illinois at Urbana-Champaign have combined muscle cells with electrical pulses to move and control a tiny 3D printed robot. Engineers hope these bio-bots can used to pave the way to a new generation of biological machines for use in energy, environment or medical environments.
This new moving bio-bot didn’t happen over night. The first iteration of the bio-bot by the same team was able to walk on its own powered by beating heart cells from rats. In this version, the engineers were unable to control the bio-bot’s movements and motion because of the constant contraction of beating heart cells. Engineers determined they needed a different kind of cell to create a bio-bot that let them control its speed, motion of just simply power it on or off.
The answer was muscle cells and electricity. Combining muscle cells with electricity gave the researchers control over the bio-bot’s movement which they lacked in the first bio-bot.
Inspired by the muscle-tendon-bone relationship in nature, the engineers 3D printed a “backbone” from a hydrogel which was strong enough to function like a joint in your body when a muscle was attached.
Just like our own biology, tendons attach the muscle to the bone. To mimic nature, the engineers used two post-like structures, like table legs, to anchor a strip of engineered muscle cells to the 3D printed backbone. Since the bio-bot needs to move, the posts are the bio-bot’s feet.
The bio-bot is less than a centimeter long (the width of a pencil) and moves through electrical pulses sent to its skeletal muscle. This gives the researchers control over how fast or slow the bio-bot moves.
According to Rashid Bashir, project lead and Abel Bliss Professor of Engineering, University of Illinois, designing machines with biological structures allows researchers to harness the power of cells and nature to address challenges facing society.
“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,” said Bashir.
“It’s only natural that we would start from a bio-mimetic design principle, such as the native organization of the musculoskeletal system, as a jumping-off point,” said graduate student Caroline Cvetkovic, co-first author of the paper which was published in the Proceedings of the National Academy of Science. “This work represents an important first step in the development and control of biological machines that can be stimulated, trained, or programmed to do work.”
Bio-mimicry is a new tool for roboticists. It’s based on principles that mimic, process and replicate nature to understand design processes. It’s not that engineers want to re-create an animal, but they want to emulate the design and living habits of that animal. So in bio-mimicry from a roboticist point of view, they would study a spider or tree frog (See Forbes: Tiny Bio-Inspired Robot Modeled From Feet Of A Tree Frog) to understand more about adhesion or sensing and how the spider or frog can serve its own needs while living and enhancing its own environment.
In this case, the team of engineers who created this new bio-bot designed it to be highly configurable for special environments like chemical analysis. In this environment, the bio-bot could act as an autonomous sensor and when it senses a specific chemical or toxin, it can move towards it the threat and neutralize the toxin.
