At SID 2014, Nokia and Semiconductor Energy Laboratory (SEL) showed off a display that can be folded in two or three while displaying video. These are 5.9-inch 720p OLED displays with a pixel density of 249ppi. These displays were built using what the company calls “WTC” structure, which is essentially a combination of white light-emitting OLEDs and color filter.
The interesting part is that these displays can be folded while they are displaying a video and can be bent up to radii of two millimeters and four millimeters respectively. The companies also claim that the displays are strong enough to survive being bent more than 100,000 times.