MIT develops water-based, intelligent Band-Aid
Engineers from the Massachusetts Institute of Technology (MIT) have designed what may be the Band-Aid of the future: a sticky, stretchy, gel-like material that can incorporate temperature sensors, LED lights, and other electronics, as well as tiny, drug-delivering reservoirs and channels. The “smart wound dressing” releases medicine in response to changes in skin temperature and can be designed to light up, if the medicine is running low.
When the dressing is applied to a highly flexible area, such as the elbow or knee, it stretches with the body, keeping the embedded electronics functional and intact. The key to the design is a hydrogel matrix designed by Xuanhe Zhao, associate professor in MIT’s Department of Mechanical Engineering. The hydrogel is a rubbery material, mostly composed of water, designed to bond strongly to surfaces such as gold, titanium, aluminium, silicon, glass, and ceramic.
The team reports embedding various electronics within the hydrogel, such as conductive wires, semiconductor chips, LED lights, and temperature sensors. Zhao says electronics coated in hydrogel may be used not just on the surface of the skin, but also inside the body, for example as implanted, biocompatible glucose sensors, or even soft, compliant neural probes. “Electronics are usually hard and dry, but the human body is soft and wet. These two systems have drastically different properties,” Zhao adds. “If you want to put electronics in close contact with the human body for applications such as health care monitoring and drug delivery, it is highly desirable to make the electronic devices soft and stretchable to fit the environment of the human body. That’s the motivation for stretchable hydrogel electronics.”