A self-healing multispectral transparent adhesive peptide glass

Despite its disordered liquid-like structure, glass exhibits solid-like mechanical properties¹. The formation of glassy material occurs by vitrification, preventing crystallization and promoting an amorphous structure². Glass is fundamental in diverse fields of materials science, owing to its unique optical, chemical and mechanical properties as well as durability, versatility and environmental sustainability³. However, engineering a glassy material without compromising its properties is challenging^4-6. Here we report the discovery of a supramolecular amorphous glass formed by the spontaneous self-organization of the short aromatic tripeptide YYY initiated by non-covalent cross-linking with structural water^7,8. This system uniquely combines often contradictory sets of properties; it is highly rigid yet can undergo complete self-healing at room temperature. Moreover, the supramolecular glass is an extremely strong adhesive yet it is transparent in a wide spectral range from visible to mid-infrared. This exceptional set of characteristics is observed in a simple bioorganic peptide glass composed of natural amino acids, presenting a multi-functional material that could be highly advantageous for various applications in science and engineering.