(Pocket-lint) - Wearables and smart clothing are going to be appearing in huge numbers in 2015 but the problem with them will always be the same – power. Or will it?

A breakthrough flexible nanogenerator, revealed at the MEMS 2015 conference last week, could fix power problems forever. The stamp-sized patch attaches to the skin and uses static electricity produced from friction to power devices, like an activity tracker. This is called the triboelectric effect.

The unit already built and shown off was able to generate 90 volts of open-circuit voltage when tapped by a finger. That's enough power to run 12 LEDs.

So how does it work? An electrode is used to harvest the current, so a 50nm-thick gold film is used. The gold film sits below a silicone rubber layer composed of thousands of tiny pillars that help create more surface area for skin contact, which creates more friction. Since the skin is a one of the triboelectric layers it means the device can be small.

Future wearables like smartwatches, activity trackers and smart clothes may no longer need such large batteries, or batteries at all. This could hail an age of super small devices that we wear which never need charging. Here's hoping they begin to appear on the market soon.

READ: Future batteries, coming soon: charge in seconds, last months and power over the air

Writing by Luke Edwards.