Our Phones Could Soon Be Powered By WiFi
Researchers from the Massachusetts Institute of Technology have found a way to convert radio signals into power which could allow phones, tablets, laptops and medical devices to run without a battery.
The researchers created a super thin, bendy 'rectenna' which is connected to a semiconductor only three atoms thick.
The device picks up WiFi and other radio-frequency signals and converts them into a direct electrical current.
It's battery-free, inexpensive, can cover very large areas, and can capture signals at low frequencies.
There are other rectennas around, but they are too rigid and fragile to make into large sheets.
"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?" paper co-author Tomás Palacios asked.
"We have come up with a new way to power the electronics systems of the future -- by harvesting WiFi energy in a way that's easily integrated in large areas -- to bring intelligence to every object around us," he said.
The rectenna has so far produced more than enough power to light up a simple mobile display (about 40 microwatts) when exposed to typical WiFi signals (about 150 microwatts) which is only an efficiency rate of between 30 and 40 percent.
The research team is now planning to build more complex systems and improve efficiency.
FYI Australia invented WiFi
In short, a physicist and engineer named John O'Sullivan was looking into Stephen Hawking's theory of evaporating black holes and subsequent radio waves when he and his team at CSRIO created the technology that now powers WiFi.
That was back in the 90's and the only reason this is no longer a thing.
We've come a long way in 20-odd years.