Audia Biagio, Tone Caterina Maria, Pagliusi Pasquale, Mazzulla Alfredo, Papavieros George, Constantoudis Vassilios, Cipparrone Gabriella
Department of Physics, University of Calabria, Ponte P. Bucci 31C, 87036 Rende, CS, Italy.
CNR Nanotec, Institute of Nanotechnology, S.S. Cosenza, 87036 Rende, CS, Italy.
Biomimetics (Basel). 2025 Jul 23;10(8):486. doi: 10.3390/biomimetics10080486.
Hierarchical surface structuring is a critical aspect of advanced materials design, impacting fields ranging from optics to biomimetics. Among several laser-based methods for complex structuring of photo-responsive surfaces, the broadband vectorial interferometry proposed here offers unique performances. Such a method leverages a polychromatic laser source, an unconventional choice for holographic encoding, to achieve deterministic multiscale surface structuring through interference light patterning. Azopolymer films are used as photosensitive substrates. By exploring the interaction between optomechanical stress modulations at different spatial periodicities induced within the polymer bulk, we demonstrate the emergence of hierarchical Fourier surfaces composed of multiple deterministic levels. These structures range from sub-micrometer to tens of micrometers scale, exhibiting a high degree of control over their morphology. The experimental findings reveal that the optical encoding scheme significantly influences the resulting topographies. The polarization light patterns lead to more regular and symmetric hierarchical structures compared to those obtained with intensity patterns, underscoring the role of vectorial light properties in controlling surface morphologies. The proposed method is fully scalable, compatible with more complex recording schemes (including multi-beam interference), and it is applicable to a wide range of advanced technological fields. These include optics and photonics (diffractive elements, polarimetric devices), biomimetic surfaces, topographical design, information encoding, and anti-counterfeiting, offering a rapid, reliable, and versatile strategy for high-precision surface structuring at a submicrometric scale.
分层表面结构化是先进材料设计的一个关键方面，影响着从光学到仿生学等诸多领域。在几种用于光响应表面复杂结构化的基于激光的方法中，本文提出的宽带矢量干涉测量法具有独特的性能。这种方法利用多色激光源（全息编码的一种非常规选择），通过干涉光图案化实现确定性的多尺度表面结构化。偶氮聚合物薄膜用作光敏基板。通过探索聚合物本体内部不同空间周期的光机械应力调制之间的相互作用，我们展示了由多个确定性层次组成的分层傅里叶表面的出现。这些结构范围从亚微米到几十微米尺度，对其形态表现出高度的控制。实验结果表明，光学编码方案对最终的形貌有显著影响。与强度图案相比，偏振光图案导致更规则和对称的分层结构，突出了矢量光特性在控制表面形态中的作用。所提出的方法完全可扩展，与更复杂的记录方案（包括多光束干涉）兼容，并且适用于广泛的先进技术领域。这些领域包括光学和光子学（衍射元件、偏振器件）、仿生表面、地形设计、信息编码和防伪，为亚微米尺度的高精度表面结构化提供了一种快速、可靠且通用的策略。
