Bioinspired High Tolerant Vein-Membrane Al2O3 Coating

The vein-membrane structure inspired by insect wings is applied to the artificial structural design of materials, with the aim of enhancing the intrinsic low strain tolerance and bonding strength of Al2O3 coating. Al2O3 platelets with high aspect ratio are used as veins, forming a bioinspired vein-membrane structure along with the Al2O3 membrane. Further, Al2O3 platelets take "root" in the substrate, forming a bioinspired root-soil interlocking structure. The greatest highlight of this coating is that it can restrict the cracks to the submicron area enclosed by the vein. The multi-bioinspired structure enabled the Al2O3 coating to sustain strains as high as 8%, which is 2 orders of magnitude higher than the reported failure strain of Al2O3 film. The bonding strength is also increased by at least five times. The vein-membrane structure opens a novel technological space for the artificial structural design of materials.