Bio-inspired curved micro-nano integrated structures with controlled light diffusion, high transmittance and superhydrophobic antifouling properties

Multifunctional microcurve and tapered nanonipple integrated structures (MTNPI) hold significant potential for development of various advanced devices. However, the fabrication of MTNPI remains challenging due to the integrated construction of micro and nano structures with complex three-dimensional morphologies. Here, a novel approach is demonstrated to fabricate diverse MTNPI exhibited controllable light diffusion, high transmittance, superhydrophobic and antifouling properties, using nanoimprinting based on novel anodic alumina oxide (AAO) templates with microcurve and tapered nanopore integrated structure (MTNNI). These templates are synthesized via a micro-confined hard oxidation technique followed by multi-step anodization and etching widening process, which employs chronological and spatial covering of polymer patterns to guide the self-growth direction of nanopores, enabling the integrated fabrication of cross-scale complex MTNNI without aiding of expensive nanotemplates or sophisticated lithographic procedures. These MTNPI not only modulate laser spots to homogeneous linear/square distributions but also exhibit a transmittance of ∼98 % across the wavelength of 400–1100 nm, and water contact angle of ∼150°. Moreover, the transmittance still remains 85.5 % even being pull out of the graph powder, while the flat is 40.2 %. Due to the industry compatible fabrication process, these multifunctional MTNPI have high potential to be applied in various advanced optical elements.