Scientists at the University of California, San Diego have created a patch that generates electricity from sweat even in sleep.

Previously, engineers have already created similar biofuel cells powered by human sweat, such as a shirt. But they all required intense activity, so the person spent more energy than he received.

Therefore, engineers have found the area of ​​the body that most often sweats, even without physical activity, these are the fingertips. They excrete 100-1000 times more sweat than any other part of the body. People do not notice this because the sweat from the fingertips evaporates quickly.

But with the help of a biofuel “patch” from it for 10 hours of sleep, you can get enough energy to power a smartwatch for 24 hours.

In a thin, flexible strip that can be wrapped around your fingertip like a patch, the carbon foam electrode pad absorbs sweat and converts it into electrical energy.

The electrodes of the wearable device contain enzymes that trigger chemical reactions between lactate and oxygen molecules in sweat to generate electricity. Also, energy is actively generated when a person types on a keyboard or plays the piano, this is due to the piezoelectric material, which generates electricity from pressure.