Electronic tattoo applied directly to the skin

Researchers at the University of Illinois have developed a technology for applying electronic sensors directly to the skin. These sensors can capture information about skin moisture and temperature, as well as signals from muscles and brain activity.

The concept of electronic tattoos is not new in itself, but the existing method of applying them requires the use of a polymer substrate, which is then glued to the skin. This makes such a tattoo short-lived, because it can easily be washed away with water.
The way developed by scientists from Illinois allows you to apply electronics directly to the skin, without using a substrate. This prolongs its service life up to several weeks, after which it will fall off due to the natural process of exfoliating the skin. Probably, in the future, it will be possible to apply such a tattoo under the skin, which will make it practically eternal.
Coupled with flexible batteries developed at the same university, this invention can give a big boost to the development of electronic tattoos. And, perhaps, in the near future they will be widely used in various areas of our life.

PDF document with a detailed description.