Currently, any form of wireless charging has to take place when the device and its charging point is completely still so the wireless power transfer, which is also known as magnetic resonance coupling, is tuned to a certain distance. Having a device detect it all the time and without prompting is difficult.
However, the research team have managed to transfer energy to a moving LED lightbulb wirelessly. This was done by replacing some components with a voltage amplifier and feedback resistor, which allows there to be an automatic check for the correct frequency.
Graduate student Sid Assawaworrarit, the study's lead author, said: "Adding the amplifier and resistor allows power to be very efficiently transferred across most of the three-foot range and despite the changing orientation of the receiving coil. This eliminates the need for automatic and continuous tuning of any aspect of the circuits."
However, the team know there are still obstacles to overcome, including increasing the electricity level "significantly" as it has currently only been tested transferring a single milliwatt.
Shanhui Fan, a professor of electrical engineering, added: "We still need to significantly increase the amount of electricity being transferred to charge electric cars, but we may not need to push the distance too much more.
"The hope is that you'll be able to charge your electric car while you're driving down the highway. A coil in the bottom of the vehicle could receive electricity from a series of coils connected to an electric current embedded in the road."