Xiaomi co-founder Bin Lin (pictured) shared a video of a folding smartphone prototype, sparking speculation the company may be readying such a device for commercial launch.

Under the hashtag InnovationForEveryone, the video sees the executive using a tablet-type handheld, before folding back the top and bottom portions to give a smartphone-size, all-screen, device.

It follows a “leaked” video posted earlier this year showing a similar device, with speculation it was from Xiaomi.

Devices with foldable screens have long been mooted, but so far have not been a commercial proposition. However, this is changing, with a number of top-tier vendors reportedly following this path.

Samsung looks set to be a front runner, with an expectation it will showcase a device at a pre-MWC Barcelona launch event, although it is far from clear how close to a commercial launch it is. Motorola is also believed to have a revival of the RAZR brand in the works, switching the clamshell form factor for a folding screen.

But, there are several issues which need to be addressed. Consumers will need to be convinced of the durability of devices, particularly as screens may be bent multiple times each day and such designs do not lend themselves well to cases. There is also the question of how apps will handle the different screen real estate available.

Price will also be a critical factor. At least initially, foldable devices are expected to be expensive, meaning this will not be a mass market proposition for the foreseeable future.