Inho Kim

Inho Kim, 34, built artificial muscle fibers that are light, flexible, and strong. He envisions them being used in wearable devices to assist people with cerebral palsy. But because his new material produces around six times more power than human muscle fibers, and can lift up to 5,000 times its own weight, it is also one of the best candidates for suits to augment the strength of people such as soldiers, construction workers, or the elderly. The fibers might also be used to build robots that move more like humans or animals. 

Exoskeleton suits already exist, but they are heavy and bulky, and they can cost up to $200,000, putting them out of reach for most people and applications. 

Kim’s solution was to replace actuator motors and rigid frames with artificial muscle fibers inspired by the real thing—made from a flexible substrate and infused with a second material to enhance movement and power. While others have attempted similar approaches, artificial muscles have so far failed to match their natural counterparts in speed, power, weight, and feedback sensing. 

Kim’s new material, dubbed Hercules fibers, is cheap to produce and scalable, because the fibers, on average around 200 microns in diameter, can be bundled by the thousands like real muscle fiber. And thanks to the use of graphene, which conducts electricity, the fibers provide real-time feedback during a contraction.

“My goal is to make reliable, commercialized, wearable robotics,” says Kim—ideally, for those most in need, like babies with cerebral palsy who are learning how to walk.