Pointlike Material Accumulation and Displacement in Azopolymer Thin Films Driven by Spatial Light Modulation

ABSTRACT We report a method for precise surface structuring of azobenzene‐functionalized polymer films using a spatial light modulator (SLM) to generate tailored vectorial light fields with controlled polarization distributions. This approach enables the direct inscription of localized surface features such as single and multiple high‐aspect‐ratio spikes and deep holes of micrometer size, harnessing the light‐induced reorientation of azobenzene molecules within the polymer matrix. The vectorial light field used to create these topographies resembles the distribution of the local optical axis of liquid crystals employed in the fabrication of q‐plates. The resulting molecular realignment induces anisotropic internal stresses, leading to viscoplastic deformation and the formation of complex, programmable surface structures far beyond the periodic patterns achievable with conventional two‐beam interference lithography. Our method confirms the Viscoplastic PhotoAlignment (VPA) model under localized excitation, while also offering a practical and reversible tool for high‐resolution surface patterning. These results establish a platform for the fabrication of programmable materials with potential applications in adaptive optics, microfluidic systems, and surface‐based sensing.