Currently, men can treat hair loss using various products or hair transplant surgery, but these treatments do not always work for everyone or can be too expensive or painful.
Stimulating the scalp with electric pulses has been shown to restore hair growth.
Scientists at the University of Wisconsin-Madison have developed a wireless patch that sticks to the scalp and generates electric pulses by harnessing energy from random body movements.
The patch is made of materials that produce electricity when they come into contact and separate again.
It was successful in growing hair in rats, with faster growth and hair density than using other methods. The team has designed a baseball cap that uses this material and is currently seeking approval to test it in men in a clinical trial.