Stretchable microLED displays without distortion? 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 is incompatible with today’s display fabrication process due to its significant thermal expansion and low dimensional stability.
Jae-Hyun Kim from KIMM (Korea Institute of Machinery & Materials) will present a solution at TechBlick's upcoming microLED event. Checkout the full agenda here www.TechBlick.com/microLEDs
This talk presents a stretchable meta-display enabled by micro-LEDs to overcome the limitations of conventional stretchable displays. As shown in slide one, an auxetic metamaterial with a Poisson’s ratio of -1 and electric interconnections was designed 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.
As shown in slide two, the auxetic metamaterial consists of kirigami-cutting lines made by the UV laser. The structural stretchability of kirigami overcomes the low material stretchability of polyimide and reaches a panel stretchability larger than 20%. The polyimide substrate has excellent dimensional and thermal stability during the circuit board fabrication.
As shown in slide three, a fully automated roll transfer machine for 4-inch panels was used to transfer micro-LEDs on the circuit board. The electrical interconnection between the micro-LEDs and the circuit board was secured by Tin-based eutectic solder. The scalability of the roll transfer technology was demonstrated by realizing two-inch, three-inch, and four-inch stretchable display panels, as shown in slide four.
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