Sweat Could Power Your Phone [VIDEO]

You're out on a run late at night and suddenly you realize you have lost your way. None of the streetlamps and sidewalks you pass by look familiar and you have the sneaking suspicion that you are a long way-away from where you intended to be.

This has likely happened to a lot of late-night runners, where the streets and sidewalks you pass every day just don't look the same at night. Normally, this is when you could whip out your cell phone and call a friend or even check a map app. But what if your phone is dead?

Just start running again. Researchers are suggesting that one day you could just slap a wired pad to your arm to charge that phone mid workout.

Of course, according to Wenzhao Jia, the experimental technology that has inspired this idea is not up-to charging phones just yet.

"The current produced is not that high, but we are working on enhancing it so that eventually we could power some small electronic devices," Jia said in a recent release. "Right now, we can get a maximum of 70 microWatts per cm², but our electrodes are only 2 by 3 millimeters in size and generate about 4 microWatts - a bit small to generate enough power to run a watch, for example."

The tiny electrodes Jia mentions look like small tattoos that are attached to a person's skin. The initial purpose of these tattoos was to pioneer the next generation of biosensors - much like the bio monitors athletes wear in the form of wrist bands and even sensor-laced shirts.

As described during Jia's presentation at the 248th National Meeting & Exposition of the American Chemical Society (ACS), the tattoo sensor works by detecting and responding to lactate, which is naturally present in sweat.

When a body is becoming exhausted and needs to generate more energy, it launches into a process called glycolysis, which produces lactate as a by-product. This chemical then slips into the blood and sweat of an athlete as they work.

Monitoring lactate production can help show how hard an athlete is working, but the researchers also found that the by-product could actually power a small bio-battery.

Right now, the bio-battery is only used to power the tattoo itself, but one day the researchers hope to use "sweat power" to do much more.

Still, even Jia admits that like a wayward runner, the technology is quite a long way away from where it needs to be.

[Credit: American Chemical Society]