Researchers at the University of Queensland have developed a new type of sensor that can measure how hard muscles are working without needles, surgery or other invasive procedures.
The breakthrough could help create smarter robotic limbs, wearable exoskeletons and rehabilitation devices that respond more naturally to a person’s movements.
The study was published in Science Robotics.
The new technology uses ultra-wideband radar sensors that sit on the skin.
Instead of directly touching the muscles or inserting equipment into the body, the sensors send harmless electromagnetic pulses into the muscle tissue.
As the muscles tighten and relax, the signals change in predictable ways. By analyzing these changes, the researchers can estimate the force the muscles are producing.
According to lead researcher Christopher Bird, a Ph.D. candidate at the University of Queensland, this is the first time scientists have been able to accurately measure muscle force in this way without using invasive techniques.
This information could be especially useful for robotic devices that help people move. Wearable exoskeletons and advanced artificial limbs are becoming more common, but many of them still rely on external measurements, such as body position or movement, to decide when to provide assistance. These methods cannot directly tell how much effort a person’s muscles are actually making.
The new radar system could change that. By measuring muscle force itself, future robotic devices may be able to respond much more precisely. For example, if a person’s muscles begin to weaken during walking, an exoskeleton could immediately provide the right amount of extra support. If the muscles become stronger, the device could reduce its assistance, making movement feel more natural and comfortable.
The technology could also improve medical care and rehabilitation. Associate Professor Taylor Dick said that doctors and therapists currently have limited ways to monitor muscle force during recovery from injuries or illness. In some rehabilitation programs, electrical stimulation is used to make weakened muscles contract, especially in people who have lost voluntary muscle control. However, these treatments can sometimes tire the muscles too quickly or even damage tissue if not carefully managed.
The new sensors may help clinicians monitor muscle performance more accurately, making these treatments safer and more effective. The technology could also help athletes recovering from injuries by providing better information about when their muscles are ready for training again, reducing the risk of returning to sport too soon and suffering another injury.
Researchers believe the sensors could also support older adults by improving assistive devices that help maintain mobility and independence as muscles naturally weaken with age.
The next goal for the research team is to make the system work in real time. If successful, the sensors could continuously measure muscle force while a person is moving and instantly send that information to a robotic limb or wearable device. This would allow the technology to adjust its level of assistance from moment to moment, creating smoother and more natural movement.
Although more work is needed before the technology is used in everyday healthcare, the study represents an important step toward assistive devices that work in harmony with the human body.
By giving robots and prosthetic limbs a clearer understanding of how muscles are working beneath the skin, this new “muscle radar” could improve mobility, rehabilitation and quality of life for many people in the future.
