(USA)

Engineers at an American university have developed a wearable biofuel cell – powered by sweat – that could provide energy for a range of mobile devices.

The stretchable cells, made by a team from the University of California San Diego, ‘extract energy from sweat’. An enzyme in the cell ‘oxidizes the lactic acid present in human sweat to generate current’.

Credit: University of California San Diego

In tests, four people wearing the patch were able to power a blue LED for around four minutes.

The researchers are looking at ways to increase the length of time it is functional.They want to develop methods to store the lactic acid, which dilutes relatively quickly, while the concentration is high – as this is the source for generating the energy.

It is the latest innovation in this area. Researchers at Michigan State University have pioneered a process that captures energy from human motion using a nano generator, meaning a phone could be powered with the swipe of a finger. While a team from the University of Massachusetts Amherst is working on textile electronics that transform clothes into power suits.