Hydrogels are used in dressings, medical electrodes, and some sensors worn on the skin. Their high water content makes them flexible, but generally limits the passage of air. An international team presents a new material that retains its moisture while allowing gases to circulate better.
This new material contains a three-dimensional network of air-filled channels. They remain open even when the hydrogel is handled or compressed.
Current hydrogel dressing for moist wound care
Image Wikimedia
The experimental hydrogel contains about 70% water. Its oxygen permeability reaches 185 barrers, a unit used to measure the passage of a gas through a material. This value is about ten times higher than that of a comparable hydrogel without an air network.
The researchers compared patches made with this material to commercial silicone patches during a 20-minute exercise. Under the silicone, the skin temperature increased by 6.5 °C. Under the breathable hydrogel, it decreased by about 1 °C.
Images and observations made after the exercise also show a significant accumulation of sweat under the silicone. The skin covered by the new hydrogel remained closer to an area left exposed to the open air. The channel network simultaneously facilitates gas exchange, vapor removal, and heat dissipation.
This property could improve the comfort of devices that need to remain on the skin for several hours. It is of particular interest for medical sensors, electrodes, dressings, and certain interfaces intended for living tissues. Better ventilation can also reduce irritation and measurement disturbances related to perspiration.
The team is now studying the integration of this air network into various functional hydrogels.