Here's a new technology that might not be the first thing that comes to mind when you think about "clean" tech: a skin patch that can transform sweat into power, enough power to run your mobile device after a run, reports New Scientist.

The patch is a flexible square just a few centimeters across that sticks to your skin. It converts perspiration into energy using enzymes that feed off the lactic acid found in your sweat, and prototypes have already been shown capable of powering a radio for two days. For biofuel cell technology, that's impressive; it generates 10 times more power than previous models.

“We’re now getting really impressive power levels. If you were out for a run, you would be able to power a mobile device,” said Joseph Wang at the University of California, San Diego, who was in the team that worked on the technology.

The patch could be a non-invasive way to keep your device fully charged while you're working out, but researchers also see it as a way to power biosensors that can monitor a user's health. Because it's powered by sweat, the most obvious application will be for athletes who want to monitor their fitness.

Everyone sweats, though, so the device could also be used to keep track of vitals for people with certain medical conditions. Sweat itself contains some important biomarkers; glucose levels in sweat are comparable to their concentration in the blood, for instance. So diabetics could use it to keep track of their blood sugar. The amount of lactic acid in sweat is also related to how efficiently a person’s muscles are working. Since the patch gets its power from lactic acid already, it's a perfect application.

“The most exciting application is wearable sensors that can monitor health conditions, then sweat could generate enough power for a Bluetooth connection so that the results could be read straight from a smartphone,” said Mirella Di Lorenzo at the University of Bath, U.K.

Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Your own sweat may soon power your phone
A new skin patch that draws energy from your sweat can power a radio for two days.