2D fracture-resistant high-entropy-oxide scaffold enabled multifunctional nanomembrane

In flexible electronics, the need for ultrathin encapsulation offering a blend of features is crucial. While metal-oxide films are often considered promising candidates, their inherent brittleness has limited their practical utility. Here, we have engineered freestanding fracture-resistant high-entropy-oxide (HEO) nanomembranes by creating an in-situ nano-oxide scaffold within hydrogels. The HEO nanomembranes exhibit ductility nearing 90% and toughness exceeding 300 MJ/m³, surpassing traditional metal and metal-oxide films, as well as many advanced 2D materials. These mechanical properties are a result of the dual-phase nanostructure, where the HEO scaffold intertwined with decomposed hydrogel chains provides hierarchical toughening mechanisms that effectively impede and deflect crack propagation. Furthermore, our nanomembranes demonstrate strong adhesion to diverse substrates and impressive optical characteristics, boasting a visible transmittance of 83.2%. Even under high-temperature and humid conditions with a ~ 5% bending strain, the nanomembrane proves effective in preventing oxidation of copper circuits.