SALT LAKE CITY — They say you are what you wear, and new biosensor technology created at the University of Utah’s College of Engineering (University) takes that somewhat literally.
Chemical engineering assistant professor Huanan Zhang has developed a process that turns clothing fabric into biosensors which measure a muscle’s electrical activity as it is worn.
Zhang and his team devised a method of taking a cotton/polyester blend and turning the fabric into sensors that measure electrical impulses generated from muscle movement.
This fabric could then measure muscle activity for patients in rehabilitation instead of biosensors attached to the skin, which are often uncomfortable, effective, and costly.
“This new method can enable clinicians to collect a muscle’s long-term electrical signals with more precision,” says Zhang. “And we can get a better understanding of a patient’s progress and therefore their therapeutic outcomes over time.”
When human muscle contracts, it emits electrical signals in the form of ions.
Zhang’s process involves depositing a microscopic layer of silver over a piece of fabric to make the material conductive and therefore receive the electrical signal from the muscle.
But having just a layer of silver is a problem, since the metal can be toxic when in prolonged contact with the skin.
To solve this problem, the researchers added a second microscopic layer of gold, which is non-toxic to the touch and and enhances the electronic signal.
The silver layer is added to clothing in a similar process to screen printing a t-shirt, with the gold layer added by an electrochemical method.
Only those areas of clothing that measure the muscle activity are coated, and then attached to wires and a portable electromyography (EMG) device that measures muscle contractions.
Repeated washing didn't affect the sensors’ efficacy.
Zhang and his team have tested the method on a compression sleeve for the forearm, but he foresees its use for other skin-tight clothing such as bicycle pants or athletic tights.
This wearable technology might one day provide readings with a digital watch, according to Zhang, as a way to monitor health on a real-time basis.
More information on this technology can be found in a paper published by the science journal, APL Materials, co-authored by University of Utah chemical engineering graduate student Taehwan Lim, and Sohee Lee from the Department of Clothing and Textiles at Gyeongsang National University in South Korea.