Charging the battery of your phone or wearable device may someday be as simple as wiggling your finger, says a new study appearing in the journal Nano Energy.
Scientists from two research centers halfway around the globe from one another developed a tiny generator made of gold sheets and a common polymer that harnesses the body’s own energy to produce power.
In a study that essentially turns the human body into a small-scale power plant, researchers from University at Buffalo and the Institute of Semiconductors at the Chinese Academy of Science created a device that pairs materials to capture an electric charge, which can deliver enough power to light up a string of LED lights.
The researchers believe the nanogenerator that they developed, which measures about a half-inch at its longest point, may revolutionize the quest to keep our electronics brimming with energy.
“No one likes being tethered to a power outlet or lugging around a portable charger. The human body is an abundant source of energy. We thought: ‘Why not harness it to produce our own power?’” said lead author Dr. Qiaoqiang Gan, associate professor of electrical engineering at University at Buffalo’s School of Engineering and Applied Sciences.
Tapping Into Triboelectric Energy
The device taps into something called triboelectric energy, which produces power when two or more specific materials come into contact with one another. In this case, the tiny power device consists of a silicon-based polymer called polydimethylsiloxane, or PDMS, situated between two thin layers of gold.
To get the device to produce enough energy, the scientists stretched one of the layers of gold, giving it a spiky appearance after releasing it. When another force rustles the spiky gold layer – such as a person’s finger moving – friction develops between the three layers, resulting in an electrical reaction.
“This causes electrons to flow back and forth between the gold layers. The more friction, the greater the amount of power is produced,” said co-author Dr. Yun Xu, professor with the Chinese Academy of Science.
The current study assessed a tiny version of the generator, and while the researchers say the device won’t be able to charge a smartphone in its present state, they found it successfully lit up a string of 48 lights, giving off 124 volts and a current of 10 microamps.
With a few tweaks, such as larger layers of gold and manipulations to the stretching technique, the device should be able to deliver more power. As those tests are underway, the team is engaging in tests on a portable battery that can capture electricity from the device and store it for use.
The materials used in the device are inexpensive and common, two factors that underscore the promise of the new findings. PDMS is a common polymer found in contact lenses and other products.
“This simple, low-cost and controllable surface modification method is promising for the development of smaller devices for future wearable and self-powered electronics and optoelectronics applications,” concludes the study.