A breathable hydrogel that keeps skin cooler under a wearable patch

MIT engineers built an air-channel hydrogel that lets skin breathe and cool during exercise, tested so far on a handful of volunteers.

Engineers led by a team at MIT have developed a hydrogel threaded with a stable three-dimensional network of microscopic air-filled channels, made by adding silica aerogel particles to a standard hydrogel recipe. The material holds about 70 percent water and, in lab tests, reached oxygen permeability of up to 185 barrer, roughly ten times that of a conventional hydrogel. The work was published in Nature in 2026, with MIT's Xuanhe Zhao as senior author.

The air channels let gas and vapor pass through. The material transmitted water vapor at 10 to 100 times the rate of silicone and polyurethane patches, and retained about 95 percent of its air permeability after 10,000 stretching cycles. In infrared imaging, skin under a commercial silicone patch rose 6.5 degrees Celsius after a 20-minute workout, while skin under the new hydrogel fell about one degree. Adapted as an ECG electrode, it recorded usable signals across ten days of continuous wear.

For health, a wearable that does not trap heat or moisture could make continuous monitoring more comfortable and cut heat stress as extreme heat becomes more common. Cheaper, longer-wearing sensors widen access to the kind of tracking now confined to clinics.

The caveats are large. Human testing was small: comfort and exercise checks involved up to ten volunteers, skin physiology just two, and the ECG comparison three. The material is not clinical-grade, is not adhesive on its own, and needs work on biocompatibility, sterilization, manufacturing and regulatory approval before any real-world use.

Source: ScienceAlert