Liquid metal nano-gyroid stretchable transparent conductor for ultra-resilient optoelectronics and electroluminescence

The brittle nature of today's displays, solar cells, and touchscreens leads to adverse economic and environmental impacts, driving the need for thin-film, flexible optoelectronics that are resistant to strain, impact, sharp objects, and liquids. This vision requires cost-effective, scalable production of ultra-resilient transparent conductors capable of withstanding millions of deformation cycles-challenges that nanowire-based electrodes have yet to overcome. In nature, particular insect wings achieve a unique blend of transparency, resilience, and lightness. This inspired us to develop liquid metal-based transparent conductors with nature-inspired gyroid-like nanostructures that outperformed nanowire-based counterparts significantly in conductivity and stretchability (7×), withstanding a record-breaking strain of 1400% and unprecedented stability over 100,000 strain cycles. Unlike nanowire-based electrodes, this electrode is simple, low-cost, scalable, and recyclable. The formation of such a nano-scaffold is beyond the reach of lithographic techniques but is enabled by our unconventional technique: graphene-assisted self-assembly of liquid metal nanodroplets into a porous 3D microstructure. We demonstrate mechanically resilient soft-matter electroluminescent displays with high light intensity and extend their applications to soft robotics, light-emitting muscles, energy harvesting, transparent heaters, and UV sensors. By harnessing the deformability of liquid metal, we demonstrate a transparent pressure-sensing film that converts any display into a pressure-sensing interface.