By Jody McCutcheon
There are already phone chargers built into treadmills and other gym equipment to allow members to charge their phones while they’re working out. Now imagine nanogenerator phone chargers capable of harvesting the energy from the vibrations of not only a workout, but a simple walk, and converting it into power for your personal devices. Well, that’s exactly what a team of academics recently did, and the implications are fascinating.
Collaboration between researchers from the University of Wisconsin, China’s Sun Yat-sen University and the University of Minnesota Duluth has developed a new nanogenerator—basically a tiny chip—that can be embedded in a phone or its outer casing to harvest the energy produced by ambient vibrations. That means cordless charging of your phone battery while you’re on the go.
Researchers describe the technology, in rather complex terms, as a “mesoporous piezoelectric nanogenerator.” But basically it harvests and converts vibration energy from a surface—like, say, the dashboard of your car—into power for the phone’s battery. Piezoelectric materials take mechanical force (like vibrations) and convert it to electricity. The nanogenerator incorporates polyvinylidene fluoride (PVDF), a common piezoelectric polymer material.
Into a thin PVDF film, researchers mixed zinc oxide nanoparticles to initiate the piezoelectric phase, thus allowing the harvesting of vibration energy. Upon etching the zinc oxide nanoparticles off the film, the researchers had multitudes of interconnected pores, or “mesopores.” These mesopores make the usually stiff material behave like a sponge; and the spongier the material, the more sensitive it is to tiny vibrations. The nanogenerator is composed of this soft, mesoporous polymer film set between two thin electrodes. With its flexibility, the film will attach to most curvy or flat surfaces, even human skin.
The technology potentially has many applications. The researchers, who described their creation in the January 27, 2014 issue of the journal Advanced Energy Materials, believe larger manufacturing processes would benefit from the scalability of the nanogenerator’s simple concept and design. They also envision self-powered sensor systems, and of course, the self-charging of all personal devices.
But this nanotechnology has already trickled down to the general public, and has inspired one skateboard enthusiast in Argentina, Soledad Martin, to use kinetic energy to transform movement into an electrical charge via a nanogenerator system. Martin’s design involves a battery case that is easily incorporated into a running shoe, allowing the wearer to go outside and move around whilst wearing the battery of their phone on their shoe. After a few minutes, just remove the lid and attach the USB cable to juice up your mobile phone right there on the street. Your foot acts like a socket! Of course, the charger comes with interchangeable straps with snap buttons so the user can match the colour to his or her shoe.
Now, there’s even more motivation to get off the sofa and move, and best of all–you’ll never run out of battery as long as you keep active.