Biomimetic Omnidirectional Antireflective Glass via Direct Ultrafast Laser Nanostructuring

Abstract

aiming to design and fabricate biomimetic structures. [7] Research in this field indicated several methodologies to develop bioinspired surfaces, exhibiting hierarchical structuring at the nano-and micro-lengthscales. [8][9][10][11] Laser fabrication is a maskless process allowing material modifications with a high precision over size and the shape of the fabricated features. [12] However, due to optical diffraction, the feature size resolution is limited to the order of wavelength (i.e., microscale); therefore, the challenge in biomimetic laser processing is to beat the diffraction limit and realize the structural complexity of natural surfaces, also, at the nanoscale. Materials' structuring using ultrashort (less than 1 ps) laser pulses, in particular, proved to be a precise and highly versatile tool to realize artificial surfaces that quantitatively mimic the morphological features and functionalities of their natural archetypes. [13][14][15][16][17][18][19] This capability comes as the outcome of the optimal combination of the ultrafast laser field and material properties that enable the production of features with sizes beyond the diffraction limit (i.e., nanoscale). A prominent example is the formation of self-organized subwavelength, laser-induced periodic surface structures (LIPSS), which have been proven an important asset for the fabrication of nanostructures with a plethora of geometrical features. [13,[20][21][22][23][24][25] This work is the first report on direct laser nanofabrication of biomimetic omnidirectional antireflective glass surfaces. It was inspired from the unique antireflection properties of the wings of the glasswing butterfly, Greta oto, and the Cicada Cretensis species. [2,3] This property is due to the presence of arrays (with periodicity in the range of 150-250 nm) of nonreflective nanosized (sub-100 nm size) pillars on both the top and the bottom surface of the wing. The current state-of-the-art technologies employed for the production of antireflection surfaces require either complex multiple steps and time-consuming procedures or chemical processes, [8,[26][27][28][29][30][31][32] which, in some cases, produce hazardous wastes. At the same time, the chemical coatings' quality tends to degrade with time. [27,33,34] Here, we demonstrate a single-step laser texturing approach for the structuring of biomimetic antireflective nanopillars, on fused silica glass (SiO 2 ) surfaces. The overall properties of the produced surfaces were found remarkably similar to the natural butterfly and Cicada archetypes, both in terms of the surface morphology Here, a single-step, biomimetic approach for the realization of omnidirectional transparent antireflective glass is reported. In particular, it is shown that circularly polarized ultrashort laser pulses produce self-organized nanopillar structures on fused silica (SiO 2 ). The laser-induced nanostructures are selectively textured on the glass surface in order to mimic the spatial randomness, pillar-like morphology, as well as the remarkable antir...

Controlling the wettability of stainless steel from highly-hydrophilic to super-hydrophobic by femtosecond laser-induced ripples and nanospikes

“…Due to the conned laser-matter interaction area, the ultrashort laser pulses gives a possibility to reach a precise structuring in the scale of micrometres by direct laser writing technique via ablation. Surface structuring by ultrashort pulses is possible even below the light diffraction limit due to generation of selforganised structures like laser-induced periodic surface structures (LIPSS) 11,[16][17][18] and nanoparticles. 10,19 The usage of stainless steel surfaces with altered wetting properties is wide and could be applied for many applications.…”

Pulsed laser deposition of the LaVO4:Eu, Ca nanoparticles on glass and silicon substrates

“…This agrees with the above described morphology of the films those are formed by separated nanoparticles and their agglomerates. Possibility of formation of the nanostructures with antireflection properties under action of ultrafast laser pulses was reported recently (Papadopoulos et al, 2019;Goodarzi et al, 2020).…”

Advances in ultrafast laser structuring of materials at the nanoscale

“…Parallel irradiation techniques can significantly increase the nanostructures production yield by taking advantage of multibeam interference or colloidal lithography [20,21] (Figure 1(h,i)), and thus large areas structured at the nanoscale become viable concepts for exploring new functionalities. Light-driven self-organization effects, singular phenomena that couple coherently light and matter, are illustrated in Figure 1(j-m), showing the transition from subwavelength periodic patterns to high-resolution regular patterns and then to multiscale relief and nanoscale roughness [22][23][24][25][26]. These functionalities are not limited to surfaces but they extend into the bulk, designing nanoscale arrangements in three dimensions [13,[27][28][29][30][31].…”