Synergistic substrate design for enhanced mechanical and optical stability in island-bridge stretchable displays

Island-bridge designs are regarded as promising platforms for stretchable displays, but their mechanical and optical reliability is limited by two distinct failure modes: interfacial delamination, driven by localized strain concentration due to mechanical mismatch, and the substrate sagging, resulting from insufficient elastic recovery after repeated stretching. In this study, an island-bridge stretchable display that incorporates a multi-covalently crosslinked polyurethane is presented, which addresses these challenges by combining reversible hydrogen bonding for energy dissipation and multi-covalent crosslinking for elastic recovery. Structural and mechanical analyses confirm enhanced hydrogen bonding density and reduced microstructural heterogeneity. Cyclic stretching, fracture, and delamination tests collectively demonstrate nearly complete elastic recovery, as well as enhanced energy dissipation and interfacial stability. Optical measurements demonstrate that the proposed substrates preserve pixel alignment and effectively suppress resolution distortion after cyclic stretching. These results highlight a robust materials strategy for enhancing both mechanical and optical reliability in next-generation stretchable displays.