Charging your phone is a a pain. Even worse, the more you use it, the faster the battery runs down. But what if the opposite we true? What if tapping, swiping, and pressing the screen actually charged the battery? That’s the promise of new tech out of Michigan State University. And it’s not just theoretical, either–researchers already have working gadgets that are powered just by your touch.
The technology uses a nanogenerator, called a biocompatible ferroelectret nanogenerator, or FENG. This is a thin film with a charge on both sides. When the film is squeezed, the relative charge between the sides changes, and electricity flows. A further breakthrough came when the researchers discovered that not only could you fold the film safely, but each folding increases the electricity that is generated. By folding the material over and over, like making a puff-pastry crust, the electricity output can be upped to levels that power gadgets. In fact, it generated enough power to light 20 LEDs.
The team, led by Nelson Sepúlveda of the Department of Mechanical Engineering, Michigan State University, constructed three devices: an array of LEDs which lights up when somebody squeezes its pressure pad; an LCD screen which “harvests energy from a user’s touch;” and a keyboard which is powered only by tapping its keys.
A modern smartphone is a relatively power-hungry device, but its most demanding component is the screen–lighting those pixels uses more energy than anything else. So this tech, which is already good enough to power 20 LEDs, looks promising. And remember, with phone makers ditching headphone jacks just to squeeze in a tiny bit more battery, every electron counts.
Perhaps, though, cellphones won’t be the target market here. A device that produces electricity when it is flexed and squeezed sounds perfect for powering wearable gadgets. Smart watches and fitness trackers are one option, but what about medical implants that harvest their power from your movements, and never have to be recharged?
Once you remove the need for batteries, many tiny, always-on devices start to make sense. And Sepúlveda’s team’s device is even biocompatible, so it could end up in a body sooner rather than later.