July 14, 2022 – Scientists from UCLA and nonprofit SRI International are experimenting with a strong, stretchy polymer to create an artificial muscle they describe as stronger and more flexible than human muscle.
Polymers are natural or synthetic substances made up of large molecules and are building blocks of many minerals and human-made materials. In this case, researchers used electroactive polymers, which are polymers that change shape or size when stimulated with electricity. They’ve become darlings of the engineering world and are now being used in technology ranging from robot fish to dust wipers.
UCLA researchers developed the muscle material out of dielectric elastomers, a type of electroactive polymer, and introduced a new process for building fake muscle that they hope will one day be applied in soft robotics, and even human implants.
“We're really excited about this new material,” says Qibing Pei, PhD, an author of the study and a UCLA professor of materials science and engineering. “At its maximum performance, this artificial muscle is way more powerful than a human muscle.”
The team’s findings were published this month in Science.
Upon testing, the researchers showed that the material not only could expand and contract like a human diaphragm during breathing, but it could also toss a pea-sized ball 20 times heavier than itself. And synthetic muscles fitted with the material were 3 to 10 times more flexible than natural muscles, according to a news release about the findings.
To create this superhuman, muscly fabric, the researchers took a common but inflexible acrylic-based material and used a UV light curing process to produce a higher-performing material. The result is a 35-micrometer film, as thin and light as a piece of human hair, which is then layered up to 50 times to create the artificial muscle sheet, the authors explain.
The artificial muscle consumes electrical energy, unlike human muscles, which use chemical energy from food to operate.
“This has a lot of advantages,” Pei says. “It is easier to control, and we can activate and deactivate the material at higher frequency. For human muscles, we generally have low performance at a high frequency.”
The researchers see a future for the technology in medical implants and soft robotics. Notably, the material can add a “sense of touch” to wearable biomedical technologies and may help those who can’t smile or blink due to health conditions, Pei explained to UPI.
“I think there is a lot of potential,” he said. “It is this new material, and I think that the implication is getting closer to reality.”