Scientists have been working with lab-grown muscle tissue for quite a while now, but the only way to trigger contractions has been electric stimulation. This requires wiring and electrodes that gently attach to tissue, and that complicates matters if you want to build something that’s powered by artificially created muscle cells.
Now researchers from MIT and the University of Pennsylvania used optogenetics to create engineered skeletal muscle cells that contract when illuminated by a 20-millisecond blue light beam. Previously cardiac cells were created using optogenetics, a technique that embeds genes that code for light reactive proteins, but the new development should be more useful in robotics and perhaps even in prostheses that will use light activated muscles made at a factory.
The light-sensitive muscle tissue exhibits a wide range of motions, which may enable highly articulated, flexible robots — a goal the group is now working toward. One potential robotic device may involve endoscopy, a procedure in which a camera is threaded through the body to illuminate tissue or organs. Asada [Harry Asada professor of engineering at MIT] says a robot made of light-sensitive muscle may be small and nimble enough to navigate tight spaces — even within the body’s vasculature. While it will be some time before such a device can be engineered, Asada says the group’s results are a promising start.
“We can put 10 degrees of freedom in a limited space, less than one millimeter,” Asada says. “There’s no actuator that can do that kind of job right now.”
Rashid Bashir, a professor of electrical and computer engineering and bioengineering at the University of Illinois at Urbana-Champaign, says the group’s light-activated muscle may have multiple applications in robotics, medical devices, navigation and locomotion. He says exploring these applications would mean the researchers would first have to address a few hurdles. “Development of ways to increase the forces of contraction and being able to scale up the size of the muscle fibers would be very useful for future applications,” Bashir says.
MIT press release: Researchers engineer light-activated skeletal muscle…
Study abstract in Lab on a Chip: Formation and optogenetic control of engineered 3D skeletal muscle bioactuators