A company called Nikola Labs has developed an iPhone case that it says can harvest energy from the air.
The company takes radio frequency signals like wi-fi, Bluetooth and 4G and turns them into power using an energy harvesting circuit. The resulting energy can be used to power mobile devices.
The smartphone case is designed for the iPhone 6 and supposedly converts the wasted energy produced by the phone to deliver a signal and puts it back into the phone so that it stays charged for 30% longer.
Phones are continually communicating with the network even when they are sitting unused on your desk.
“The phone will be sending and receiving information [for things like apps running in the background] all the time,” explains David Jazani an expert in energy harvesting from the University of Bedfordshire.
“If they are clever, what they have done is placed a collector antenna very close to the transmitting antenna, tuned to the correct frequency. Then it can harvest the signal when it is not necessary,” he says.
While energy harvesting is possible, Jazani thinks that the 30% battery life extension sounds unlikely.
The case would also have to be smart enough not to harvest energy when the phone was in use – or else it could run the battery down further and affect the phone’s performance.
“If the device is taking energy from the radio frequency signal emitted by the phone then it will reduce the range and performance of the device, which will respond by increasing output power, so it will effectively cause the phone to drain the battery faster,” says a cautious Stephen Beeby, professor of electronic systems at the University of Southampton.
“Because of efficiency losses the system will only harvest a fraction of the energy emitted by the phone and therefore more energy will be lost than gained and the net effect will be to shorten battery life,” he adds.
There is also ambient radio frequency energy in the air which can be converted into power, but traditionally it’s only been possible to harvest a small amount of electricity – enough for tiny sensors.
“But there may be opportunities to use this energy supply in the future,” says Beeby.
The iphone case prototypes just arrived from @LR_LaserRepro. Excellent work! @3dsystemscorp #asseenincolumbus pic.twitter.com/6SB1ftMhwE
— Nikola Labs (@NikolaLabs) May 1, 2015
The product was pitched on stage at TechCrunch Disrupt and the plan is to launch the product within a year.
It draws upon technology developed at Ohio State University.
The case will be available for pre-order through Kickstarter next month for $99.
If you are looking to prolong your battery life here are some good tips.