Polymer Microarray with Tailored Morphologies through Condensed Droplet Polymerization for High‐Resolution Optical Imaging Applications

Nature-inspired functional surfaces with micro- and nanoscale features have garnered interest for potential applications in optics, imaging, and sensing. Traditional fabrication methods, such as lithography and self-assembly, face limitations in versatility, scalability, and morphology control. This study introduces an innovative technology, condensed droplet polymerization (CDP), for fabricating polymeric micro- and nano-dome arrays (PDAs) with readily tunable geometric properties-a challenging feat for conventional methods. The CDP process leverages free-radical polymerization in condensed monomer droplets, allowing rapid production of PDAs with targeted sizes, radii of curvature, and surface densities by manipulating a key synthesis parameter: the temperature of a filament array that activates initiators. This work systematically unravels its effects on polymerization kinetics, viscoelastic properties of the polymerizing droplets, and geometric characteristics of the PDAs. Utilizing in situ digital microscope, this work reveals the morphological evolution of the PDAs during the process. The resulting PDAs exhibit distinct optical properties, including magnification that enables high-resolution imaging beyond the diffraction limit of conventional microscopes. This work demonstrates the ability to magnify and focus light, enhancing imaging of subwavelength structures and biological specimens. This work advances the understanding of polymerization mechanisms in nano-sized reactors (i.e., droplets) and paves the way for developing compact optical imaging and sensing technologies.