SALT LAKE CITY (ABC4) – An engineering professor at the University of Utah has developed a process that turns clothing fabric into biosensors that can measure a muscle’s electrical activity as it is worn.
Chemical Engineering assistant professor Huanan Zhang published a paper that explains how he and his team devised a method of taking ordinary textile made of a cotton/polyester blend and turning the fabric into sensors that measure electrical impulses generated from muscle movement.
The paper was co-authored by U of U chemical engineering graduate student Taehwan Lim and Sohee Lee from the Department of Clothing and Textiles at Gyeongsang National University in South Korea.
This breakthrough can be a solution in measuring muscle activity for physical rehabilitation or for other medical applications. This is because current bioelectrical sensor technology in which they tape sensors with wires to the skin can sometimes be ineffective, uncomfortable, expensive, and costly to manufacture, researchers say.
“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 (as opposed to electrons from an electrically powered device). 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 somewhat toxic when in prolonged contact with the skin. So the researchers also deposit a second microscopic layer of gold, which is non-toxic to the touch. The gold not only protects the skin from the silver, but it also enhances the electrical signal, Zhang says.
The silver layer is applied to the fabric in a process similar to screen printing a graphic onto a T-shirt, and it’s applied to just the areas of the clothing that touch the muscle being measured. Then the gold layer is deposited by an electrochemical method. The patches of sensors are then attached to wires and a portable electromyography (EMG) device that measures muscle contractions.
Currently, Zhang and his team have tested the method on a compression sleeve for the forearm. While this technology would mostly be used on compression sleeves or socks since it requires the clothing to constantly touch the skin, Zhang imagines it could also be used for other skin-tight clothing such as bicycle pants or athletic tights.
