A new antenna design aims to solve the two major problems with wireless charging: the mess of standards and the limitations of transmitting power by radio.
The antenna, built by Chicago company NuCurrent, can support the wireless charging standards of Qi, the Power Matters Association (PMA) and the Association for Wireless Power (A4WP), which means that although Qi seems to be winning the battle, you don’t have to match your phone to the charger to be sure.
The core technology from NuCurrent is ML Wire, which CEO Jacob Babcock describes as “like bundling 10 drinking straws passing through liquid”. This was designed to optimise the conductive frequency in a situation where the antenna was pressed against skin.
As the rival charging standards use different frequencies – Qi is 110 and 250kHz while PMA is 200 to 300 kHz – the NuCurrent design has to cope with managing the heat differently. The A4WP standard being at 6.78MHz, however, means it needs an additional coil.
By lowering the wires' resistance, there is a power saving which translates into an efficiency saving, so that the phone or smart watch doesn’t get quite so hot when charging. It’s akin to Litz wire, which is a multi-strand magnetic wire meshed together in a geometric shape.
The ability to power devices through skin has obvious medical applications: however, the technology is likely to have a wider appeal in phones and watches. ®