With the Galaxy Fold hitting shelves this week, followed soon by the Mate X, the stage is set for the next big trend in smartphones: foldable smartphones. Currently there are still many limitations to what manufacturers can do in terms of form factor, but, hopefully, soon the battery will not be one of them.

A team of researchers from ETH Zurich, led by Professor Markus Niederberger, have developed a prototype of a battery which can be bent, folded, or stretched, without interrupting the power supply.

To date, no one has employed exclusively flexible components as systematically as we have in creating a lithium-ion battery — Markus Niederberger

Future usage scenarios could go way beyond foldable smartphones, with rollable displays, smartwatches, tablets, and more being on the list of possible candidates. As for the technology, there’s a cathode, a hydrogel electrolyte, a PDMS frame and sealing, as well as an anode sandwiched between two stretchable current collectors.