News Items from UNC Greensboro

Picture of Dr. Hemali Rathnayake holding a prototype of a miniature solar cell.

Imagine charging your cell phone outside using only a tiny sticker on the back – no cord or pad needed. Thanks in part to UNCG’s Dr. Hemali Rathnayake, solar-powered cell phones could be the wave of the future.

Alongside collaborators from University of Louisville, Rathnayake is developing smaller, more energy-efficient, environmentally-friendly, inexpensive solar panels. Her research has received $1.5 million in grant support from NASA, the National Science Foundation and other funders.

“Our goal is for you to be able to go to Walmart, buy your solar panel, pull off the sticker and put it on your window,” says Rathnayake, an associate professor in UNCG’s Joint School of Nanoscience and Nanoengineering. “That’s the dream. It needs to be plug and play.”

To meet this goal, she’s using carbon-based nanoparticles, roughly one-millionth of a millimeter in size, to build flexible solar panels. They’re bendable, making them useful in more places than existing rigid silicon panels. The unique structure of the particles, which incorporate many void spaces, also makes the panels lightweight.

In addition to being small – roughly 4 centimeters by 8 centimeters – they use less sunlight energy to create the same amount of electricity as a silicon panel, she says. They produce voltage equivalent to a small battery, and, while they don’t outlast silicon panels, they do cut production costs by 25 percent. Carbon-based panels are also more environmentally friendly because they don’t include heavy metals that become toxic when processed.

Ultimately, she envisions being able to use a spray can, much like an airbrush used to paint a car, to coat the carbon solar cell solution on any surface.

Rathnayake is also interested in harnessing waste energy – energy produced, but not captured – for electricity production. In particular, she’s investigating thermoelectrics, the direct conversion of temperature differences into electric voltages.

She’s working on a device that uses body heat to power electronic devices. For example, the body heat you produce while jogging could be used to run – and recharge – the mp3 player playing your music.

Overall, she says, the impetus behind her research is bringing electricity to the public in a more effective, affordable form.

“I come from a country where sunlight is abundant, but electricity isn’t,” she says. “Electricity isn’t affordable for all families. That’s the reason we’re thinking about doing this in an environmentally-friendly, cheaper way.”


This post was adapted from a UNCG Research Magazine story written by Whitney J. Palmer. To read the full story and more, click here.
Photography by Mike Dickens

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