Stretchable Micro-LED Display without Image Distortion

Stretchability is the ultimate target in flexible displays. There are three significant hurdles in the commercialization of stretchable displays. First, the stretching of display panels inevitably accompanies image distortion and non-uniform deformation. Second, the conventional display substrate suffers from low stretchability. Third, the stretchable rubber substrate [1] is incompatible with today’s display fabrication process due to its significant thermal expansion and low dimensional stability. This talk presents a stretchable meta-display [2] enabled by micro-LEDs to overcome the limitations of conventional stretchable displays. An auxetic metamaterial with a Poisson’s ratio of -1 and electric interconnections was developed as a substrate of the stretchable display for stretching without image distortion and with uniform deformation. A highly stretchable circuit board was realized using a polyimide substrate, a conventional display substrate for commercialized OLED flexible displays. The structural stretchability of kirigami overcomes the low material stretchability of polyimide and reaches a panel stretchability of 24.5%. In addition, roll transfer technology was used to interconnect the micro-LEDs with the circuit board reliably, and its scalability was demonstrated by realizing a three-inch stretchable display panel.