A Taiwanese company is demonstrating two-way touch charging this week at the Computex exhibition, using a new chip that allows two people to share one phone's battery by holding their devices together.

In a demonstration on the show floor, two iPhones with external battery packs containing the chips were pressed together back-to-back. One phone was used to charge the other, then after the settings on the external batteries were switched, power flowed in the opposite direction.

Winstream, a Taiwanese manufacturer of power supplies and charging technology, says it will begin mass producing the chip by September. It is roughly the size of a contact lens, so phone and tablet manufacturers should be able to easily fit it into their devices, said Sales Director Kevin Chi. It will cost about $4 per unit, double the price of a one-way touch charging chip. The external battery packs are for demonstration only.

Chi said his company is in talks with many big-name manufacturers that have shown interest.

"Almost everyone you can think of," said Sales Director Kevin Chi. "But not so many in the U.S."

He said that larger batteries tend be more efficient with wireless charging, so a tablet or laptop would be better suited to charging a mobile phone than the other way around, although either is possible. He said charging with the technology occurs at about the same rate as when a device is physically plugged in.

Touch charging is a major theme at this year's Computex exhibition, with some companies pairing it with wireless data technology so that no plugs are required to re-juice and sync a device.

Winstream, which began developing wireless charging about five years ago, believes it is the first to offer a two-way solution.

The company demonstrated the technology at the Computex exhibition taking place this week in Taiwan. The show, featuring electronics and component makers, is one of Asia's largest.