Fig. 5: Wrinkling characteristics of the textile-based OLEDs.

a Photograph of the multi-axis tensile test machine used for the multi-directional wrinkling test. b Schematic image of the wrinkling test condition according to the relative cell area (reference condition: relative area 100% and wrinkling condition: relative area 75–28%). c Photograph of various wrinkled shapes (left: pop-down, middle: random, and right: pop-up). d Normalized luminance of the repetitive wrinkling cycle of parylene-C textile in this study (solid line) and SU-8 textile in a previous study (dotted line)¹⁶, the initial luminance: 1000 nit. e Photograph of a parylene-C textile-based OLED cell after wrinkling (relative area: 75, 53, 36 and 28%, wrinkling cycles: 0 (before), 50 and 100 cycles).