M2E Power, a company formed last year to , has reported back that its system actually works.
Next year it expects to release a charger that can harvest enough motion from walking to replenish cell phones or other small gadgets, like GPS devices.
It says that six hours of cumulative motion can add 30 to 60 minutes of talk time to a cell phone.
The idea is to place the charger inside a purse or backpack and let it charge in the background, said Regan Rowe, director of business development at the company. When fully charged, M2E Power's device stores enough to recharge a phone at a speed comparable to an AC outlet.
Inside is a lithium ion battery and a series of coils and magnets. When it moves, an electromagnetic field forms around the coils to generate electricity.
The technology, developed in part at Boise State University, optimizes that field to match the slow frequency of human motion and draw a usable current.
The charger unit can be charged by an AC wall socket as well. M2E Power has had discussions with cell phone manufacturers to build the generator directly into a phone.
"Handset manufacturers are under pressure to deal with electronic waste issues and show they are looking for more sustainable practices," Rowe said. "We've seen a lot of interest in this as the wave of the future."
But because those products take a few years to design and develop, it will likely take at least two years before a self-powered cell phone is commercially available, Rowe said.
The company is also testing how much charge it can draw from the vibration of vehicles, Rowe said. The amount of charge a generator can make varies a great deal with the amount of motion.
"Someone with an old pick-up truck with no shocks will have a glorious time with M2E technology, but someone with a Mercedes will have to spend more time" charging, she said.
Long term, the company is looking at placing self-charging devices in hybrid and electric cars. Putting a self-charging device near windshield wipers or door locks could significantly cut down on a hybrid car's electrical load and extend its driving range, Rowe said.
The company also has military grants to explore the use of self-powering devices such as night goggles.