MIT researchers have developed an electronic skin technology that contains artificial sweat ducts. The ducts prevent the accumulation of sweat under the electronic skin, helping to prevent interference with the built-in sensors. Incorporating a kirigami-style design, the material adapts to human skin, but maintains high porosity and reduced sweat buildup. The design should help the electronic skin stay in place for extended periods, allowing the built-in sensors to monitor health during that time.
Portable patches or “e-skin” are a hot research area today, with the ultimate goal of unobtrusive health surveillance that does not require bulky and uncomfortable control devices. Technology is constantly evolving and the latter device addresses a problem facing all electronic skin technology: sweat. Our skin constantly produces moisture and, if it cannot escape through an electronic skin patch, it will build up, which can cause the sensor to malfunction or come off.
“Sweat can build up between the electronic skin and the skin, which can cause skin damage and sensor malfunction,” Jeehwan Kim, one of the developers of the new electronic skin, said in an MIT ad. “So we tried to address these two issues at once, allowing sweat to permeate the electronic skin.”
Previous electronic skin technologies have tried to make these devices breathable by using woven fibers, for example, but sweat has been a stubborn challenge. Initially, these researchers designed simple films with regular holes that would allow sweat to escape. However, even though this design let out sweat, the resulting electronic skin was not flexible enough and broke easily. To avoid this problem, the researchers used a kirigami-style design, which incorporates small cracks between the pores of the electronic skin, providing flexibility and strength along with the diffusion of sweat.
“If you wrap a piece of paper over a ball, it’s not compliant,” Kim said. “But if you cut a kirigami pattern on paper, it could conform. So we thought, why not connect the holes with a cut, to have a kirigami-like conformation on the skin? At the same time, we can permeate sweat. “
The electronic skin is made with ultra-thin semiconductor films and researchers have already tested it on a volunteer who wore it for more than a week. During this time, the patch measured hydration levels, temperature, pulse, and UV exposure. Investigators informed the volunteer, asking him to run 30 minutes on a treadmill and eat a spicy meal to produce a lot of sweat. Electronic skin remained under this punishment.
“With this breathable, conformable skin patch, there will be no accumulation of sweat, incorrect information or peeling of the skin,” Kim said. “We can provide usable sensors that can do constant monitoring in the long run.”
Study a Scientific advances: Reliable long-term physical health monitoring using perforated electronic skins inspired by sweat pores