A thin and flexible sheet devised by researchers could absorb energy from the environment to help charge devices like phones and tablets, according to The Guardian. The device can create power out of thin air – so long as the air contains Wi-Fi signals or other electromagnetic waves.
The researchers, from Massachusetts Institute of Technology (MIT) were led by Tomás Palacios, and published their findings in the journal Nature on Monday.
The material takes in wireless internet or radio waves, and converts them to usable electricity.
According to the authors, the device has potential far beyond just charging today’s portable devices without a conventional power source.
“What if we could develop electronic systems that we wrap around a bridge or cover an entire highway, or the walls of our office and bring electronic intelligence to everything around us? How do you provide energy for those electronics?” Palacios said in a statement. “We have come up with a new way to power the electronics systems of the future – by harvesting Wi-Fi energy in a way that’s easily integrated in large areas – to bring intelligence to every object around us.”
Palacios says everything from a tablecloth to wrappers for buildings could be designed to harvest energy from the air.
The researchers attached an antenna to a super-thin semiconductor, which at only a few atoms thick is effectively two-dimensional. The antenna picks up signals from Wi-Fi and radio waves and converts them to an alternating current. Then, the semiconductor turns that into a direct electrical current.
The researchers’ model converts at 30 to 40 percent efficiency, with an output of about 40 microwatts from signals in the lab with about 150 microwatts of power.
“It doesn’t sound like much compared with the 60 watts that a computer needs, but you can still do a lot with it,” Palacios said.
For example, environmental, chemical, or biological sensors can run on just a few microwatts. The energy could also be stored for later use in a battery.
“When you have one of these energy-harvesting devices you are collecting energy 24/7 and you could be storing that in a battery to use later. You could cover your desk with an electronic tablecloth and even though you’re only at the desk for so many hours a day, it would be harvesting energy the whole time,” according to Palacios.
The team now plans to work on boosting the system’s efficiency.
Since these waves travel through the human body, the system could even be used to allow implants or “smart pills” to transmit data from inside the human body.
“In the future, everything is going to be covered with electronic systems and sensors. The question is going to be how do we power them?”