This is Scientific American 60 Second Science.

I'm Christopher Intagiyata.

The flat lithium ion batteries that power smart watches

are built by stacking the battery components,

positive and negative electrodes, current collectors, and a separator.

It's akin to piling up sheets of paper. You get a stack that you can bend or roll, but you can't stretch it.

But now researchers have designed what could be a much

friendlier battery for wearables, one that's bendy and stretchy instead of a little

brick. They built the bendy battery by starting with a coiled wire, sort of like a little slinky, and then layered

the traditional battery components, electrodes and all that, on the coil to build a silver zinc-based battery.

And the result, once the battery is flexed, it experiences very minimal stresses.

Like you can imagine flexing the slinkier.

You can easily flex it.

A la Zamoraiva, a material scientist at UC Berkeley.

That's why we were able to flex this battery for 17,000 times

while we were cycling it in situ without decreasing

electrochemical performance.

She and her team built even stretchier batteries using

serpentine designs.

Imagine squiggly lines of battery embedded in a transparent polymer that looks sort of like a bandaid.

When you pull the ends of the bandaid, the squiggle elongates, offering stretchiness at larger scales.

The studies in the journal Science Advances.

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