How to Charge Your Phone With Sweat

What is your biggest gripe with smartphones? We wouldn’t mind betting the answer is ‘battery life’. As functionality becomes more complex and graphics more dazzling, phone batteries are feeling the strain. Back when our phones were simple devices used solely for calling or texting, battery life was not an issue. But now that we use our smartphones to socialise, watch videos, play games and even do a spot of shopping, they’re hooked up to the mains charger a little too frequently.

Smartphone usage shows no signs of slowing. Apple has just released its iPhone 6, while the likes of Samsung continue to innovate using their Android-powered handsets. No matter which camp you sit in - iOS, Android, BlackBerry - it’s likely your smartphone is your most-used gadget. But that leaves us with one big problem - how do we combat short battery life without hovering near a plug socket?

According to a team of scientists at the University of California, there is one ingenious solution on the horizon. They have discovered a renewable, accessible and somewhat ingenious solution - using your own sweat to charge your phone!

Smartphones and the science of sweat

The discovery of sweat-power was a happy coincidence. The research project was initially set up to monitor athletic performance, by measuring lactate levels in sweat via a small temporary tattoo. At the American Chemical Society meeting, the team revealed that this tattoo became a ‘biobattery’, with the potential to charge smartphones among other gadgets.

So what’s the science behind sweat-power? When we exercise, our body uses a process called glycolysis to generate energy, and a substance called lactate. Interestingly, the more unfit we are, the more lactate our bodies tend to produce. To create power, researchers placed a lactate sensor onto tattoo paper. Then, to generate an electrical current, an enzyme was introduced to the sensor. This stripped the lactate of electrons, which were then passed from an anode to a cathode to produce electricity.

An another recent example of a biobattery is the new Microbiol Fuel Cell (MFC) which is powered by microbes in sewage and also cleans up the sewage it uses for power. Amazing! Dr Orianna Bretschger, from the J. Craig Venter Institute, Maryland, has published their results, which you can read more about this this article: Is free wastewater treatment on the horizon?

What does the future have in store for sweat power?

The discreet tattoo is the first of its kind. The technology is still in its infancy - with the power to produce just four microwatts - but the team believes this is the tip of the iceberg. They fully intend on powering small electronic devices, including smartphones, with sweat. Having teamed up with a start-up, the plan is to put the product into development.

Right now, the scientists have some challenges on their hands. To make the product useful, they need to increase the amount of power created - by increasing sensitivity to lactate or incorporating multiple biofuel cells. Then they need store current, before developing a way to actually hook up phones and other devices for charging.

According to lead researcher Dr Jia, sweat-powered charging has some significant advantages compared to conventional batteries. He said, "They recharge more quickly. They are safer as there is no risk they will explode or leak toxic chemicals. And they use a renewable energy source. You."

One thing’s for sure - this is an innovative and exciting answer to the frustrating problem of short battery-life!

Beyond Sweat Power

Harvesting energy from sweat is a fantastic and exciting development, but have we exhausted every avenue? And where else can we get our electricity from in the future? This blog takes a look at 5 surprising sources of green energy you might not have heard about.