Your alarm goes off and you muster your self-discipline to skip the snooze and roll out of bed. You lace up your shoes, grab your earbuds, and head out the door—only to realize your iPod is dead. Frustrated? One day the reality may be that the sooner you start sweating, the sooner your device will start charging: University of California San Diego (UCSD) researchers announced at this week’s American Chemical Society national meeting that they’ve developed a sensor and battery that can turn your sweat into usable energy. (Wow.)
It works like this: The team developed a sensor for lactate, a chemical naturally present in sweat. The sensor, which goes on your skin like a temporary tattoo, contains an enzyme that strips electrons from lactate to generate an electrical current. The team then developed a biobattery which stores the electrical current generated in the patch, making it available to use as a power source.
This technology is exciting for two reasons: The sensor alone allows doctors to more easily measure lactate levels, which can help in diagnosing conditions like heart disease, and help training athletes determine their lactate threshold and when they’re about to hit an energy wall. The second is that this biobattery means your sweat could one day power those small electronics.
But while it’s exciting to think that each pedal stroke and bicep curl could keep your tunes pumping, don’t throw out your chargers just yet. Right now, the patch can only generate about four microWatts of power—not even half of the juice required to run a basic watch, explains Wenzhao Jia, Ph.D., of the UCSD research team. And, unfortunately, the fitter you are, the less lactate your body produces. But Jia and her team plan to enhance the power output and increase the battery’s storage capability. She hopes the sensor and battery will one day be strong enough that even the low lactate levels of ultra-fit marathon runners could power small devices like a heart rate monitor or smartphone with every step of the 26.2 miles.