Biaxially Stretchable Active-Matrix Micro-LED Display with Liquid Metal Interconnects

A stretchable active-matrix (AM) display is a next-generation display that breaks away from displaying limited information on flat and curved screens. However, the implementation of stretchable displays requires much more complex fabrication processes and meticulous efforts compared to traditional flat/curved displays. Here, the biaxially stretchable AM micro-light emitting diode (LED) display on polydimethylsiloxane (PDMS) with liquid metal (LM) interconnects is reported. The pixel islands consisting of oxide TFTs and micro-LEDs, which are fabricated on the polyimide (PI) substrate, are formed through green laser cutting and transfer to the PDMS substrate. LM interconnects integrate on the pixel island and PDMS by a lift-off process. The oxide TFTs and micro-LEDs comprising the 2T1C (2 TFT + 1 capacitor) pixel circuit on the PI island, along with LM interconnects, demonstrate stable electrical characteristics even under a relaxed state as well as when biaxially stretched up to 24%. For 24% stretching of display pixels with the same ratio of PI island and LM interconnects, the LM interconnects operate at 48% stretching. The combination of pixel island array and LM interconnects successfully demonstrates the implementation of a two-axis stretchable display capable of displaying characters of A, D, R, and C through AM driving. A biaxially stretchable active-matrix (AM) micro-light emitting diode (LED) display with liquid metal (LM) interconnects is successfully demonstrated. The stretchable display covers the fabrication of micro-LED on the backplane, formation of pixel island, transfer to the stretchable substrate, and LM interconnects using a lift-off process. Stretchable AM display can be fully operated under relaxed and biaxially stretched states of 24%.image

Automated summary

This study presents a biaxially stretchable AM micro-LED display with liquid metal interconnects. The display can operate both in relaxed and stretched states up to 24%, and successfully displays characters A, D, R, and C through AM driving.