A team of engineers from Duke University has demonstrated a new technology that greatly extends the range and efficiency of wireless power transfer.
The so-called 'superlens' uses a grid of copper coils that act in unison to focus the magnetic field created by each onto a single point. The intensity of the magnetic field follows a cone-like pattern with the point of the cone representing the highest level of induction.
The new method allows for wireless power transfer to not only have a greater range but also be more efficient, with existing solutions for range extension relying on large coils or higher power output.
Although the current prototype is large and has a fixed focus Yaroslav Urzhumov, assistant research professor of electrical and computer engineering at Duke University, says the technology could be refined for use in much smaller devices and that it could use a variable focus. With these refinements he hopes the technology could be used to, for instance, charge mobile devices as they move around in a room.
“The true functionality that consumers want and expect from a useful wireless power system is the ability to charge a device wherever it is – not simply to charge it without a cable,”
“Previous commercial products like the PowerMat™ have not become a standard solution exactly for that reason; they lock the user to a certain area or region where transmission works, which, in effect, puts invisible strings on the device and hence on the user. It is those strings - not just the wires - that we want to get rid of.”
Link: Duke University