Wednesday, 30 July 2014
masthead+quote+image
Advanced search

Researchers claim lens could aid wireless power transfer

The efficiency of wireless power transfer systems could be improved by incorporating a lens made from metamaterials, US researchers claim.

A team from Duke University in Durham, North Carolina, and the Mitsubishi Electric Research Laboratories in Cambridge, Massachusetts, carried out the latest feasibility research.

When a changing electric current flows through a wire it generates a magnetic field, which in turn can induce a voltage across a physically separate second wire. Called inductive coupling, this electromagnetic phenomenon is already used commercially to recharge devices such as cordless electric toothbrushes and mobile phones, as well as in more recently developed experimental systems that can, for example, wirelessly power a light bulb across a distance of more than two metres.

Finding a way to increase the inductive coupling in such systems could improve the power-transfer efficiency.

To this end, a ‘superlens’ has a property call negative permeability, meaning it can refocus a magnetic field from a source on one side of the lens to a receiving device on the other side.

By running numerical calculations, the team determined that the addition of a superlens should increase system performance, even when a fraction of the energy was lost by passing through the lens.

The team also considered materials with magnetic anisotropy, meaning the magnetic properties are directionally dependent. Its results suggest that strong magnetic anisotropy of the superlens can offer further improvements to the system, such as reduction of the lens thickness and width.


Have your say

Mandatory
Mandatory
Mandatory
Mandatory

My saved stories (Empty)

You have no saved stories

Save this article

Digital Edition

The Engineer July Digi Issue

Poll

London Mayor Boris Johnson is lobbying for a £10 additional charge for diesel cars to drive into Central London by 2020, and for road tax on diesel cars and all pre-2006 cars to be increased, to counter air pollution. What option most closely matches your opinion on this?

Previous Poll

Europe's largest tidal array in the Pentand Firth off Orkney will eventually generate up to 86MW of power. What will it take for tidal energy to make an appreciable contribution to the UK's energy needs?

Read and comment on the results here