3D printed muscle-powered bio-bots walk on command
Baku, July 4 (AZERTAC). Cell-based soft robotic devices could help us to design machines and systems that can sense and respond to complex environmental signals.
Engineers at the University of Illinois at Urbana-Champaign demonstrated on Wednesday a class of 3D printed walking "bio-bots" powered by muscle cells and controlled with electrical pulses.
The group, led by Rashid Bashir, Abel Bliss Professor and head of bioengineering at the University of Illinois, has been a pioneer in designing and building bio-bots. In 2012, they developed a walking bio-bot powered by heart cells. However heart cells constantly contract, which makes difficult for researchers to control and to engineer a bio-bot that can be turned on and off, sped up or slowed down.
The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse. The bots are designed to mimic the muscle-tendon-bone complex found in the body.
"Skeletal muscles cells are very attractive because you can pace them using external signals," Bashir said. "For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal. To us, it's part of a design toolbox. We want to have different options that could be used by engineers to design these things."
The structure of the bio-bot was made from a synthetic hydrogel using stereolithographic 3D printing, which is strong enough to give the bio-bot structure but flexible enough to bend like a joint. The 3D printing "boasts a short fabrication time, potential for scalability, and spatial control," write the researchers in a published paper. Two posts serve to anchor a strip of muscle to the backbone, like tendons attach muscle to bone, but the posts also act as feet for the bio-bot.
The frequency of the electric field determines the bio-bot's speed. A higher frequency causes the muscle to contract faster, thus speeding up the bio-bot's progress.
Next, the researchers will work to gain even greater control over the bio-bots' motion, like integrating neurons so the bio-bots can be steered in different directions with light or chemical gradients. On the engineering side, they hope to design a hydrogel backbone that allows the bio-bot to move in different directions based on different signals.
Thanks to 3D printing, engineers can explore different shapes and designs quickly. Bashir and colleagues even plan to integrate a 3D printer into undergraduate lab curriculum so that students can design different kinds of bio-bots.
Reseachers hope that one day this system could eventually evolve into a generation of biological machines that could aid in drug delivery, surgical robotics, 'smart' implants, etc.
"The idea of doing forward engineering with these cell-based structures is very exciting," Bashir said. "Our goal is for these devices to be used as autonomous sensors. We want it to sense a specific chemical and move towards it, then release agents to neutralize the toxin, for example. Being in control of the actuation is a big step forward toward that goal."
Other news in this section
