Lightweight Soft Exosuit Shows Promise for Reducing Walking Fatigue

Researchers in China have developed a prototype robotic suit that could one day help people walk with less effort, potentially allowing older adults to remain active longer.

The device, created by engineers at Hebei University of Technology, weighs just 4.2 pounds and fits around the waist and thighs like a lightweight harness. Unlike traditional powered exoskeletons that rely on bulky motors and gearboxes, this system uses thin, flexible artificial muscles positioned near the hips to assist with each step.

The technology centers on a rubber-like material called a dielectric elastomer. When exposed to an electric field, the material changes shape, allowing it to act like a mechanical muscle. The research team, led by Wei Yu, modified the material's molecular structure to generate enough force to actually help move a human leg—something earlier versions could not accomplish. The elastomer is rolled into long, thin fibers and bundled together, similar to how real muscle tissue works.

During treadmill tests with six healthy adults, participants used 13.9 percent less energy when the powered assistance was active compared to walking without the suit. Sensors tracking muscle activity confirmed that the legs worked less during each stride.

The suit works by having the artificial muscles pull at precisely the right moment during the walking cycle, helping swing the leg forward. Straps transfer that pulling force from the fibers to the wearer's hips and thighs. A compact battery pack provides the electrical power needed to activate the system. The flexible design moves with the body rather than restricting it inside a rigid frame.

Laboratory testing showed the actuators could complete more than 100,000 cycles, suggesting reasonable durability for the components. The team also designed modular connectors so additional fibers can be added when an application requires more pulling power.

"We wanted to create something that moves naturally with the body," the researchers noted in their paper published in the journal Science Advances. The design intentionally avoids the heavy motors, noisy air pumps, and restrictive frames common in existing powered exoskeletons.

Despite the promising results, significant obstacles remain before the technology could reach consumers. The current prototype has limited battery life, restricting how long it can provide assistance. The control system also requires improvement to automatically adjust when a person speeds up, slows down, or encounters uneven terrain. Additionally, dielectric elastomer actuators typically require more than 1,000 volts to operate, raising safety considerations for a wearable device.

Researchers acknowledged that walking on grass, climbing slopes, or navigating real-world environments would present challenges the treadmill tests did not address. Questions about how the materials respond to sweat, temperature changes, and repeated bending during daily activities also need answers.

The study participants were all healthy adults, meaning dedicated research involving older individuals and those with mobility impairments is still needed. Balance and fall prevention were not examined in this initial work.

Experts say a device that meaningfully reduces walking effort could help people maintain independence as they age. Tasks like navigating large stores, walking through airports, or spending extended time with family might become less exhausting.

No timeline or price has been announced for any commercial version. The research team indicated the next phase of testing will involve older adults in more realistic settings to determine whether the artificial muscles can genuinely help people stay active and independent.