Wet‐Style Superhydrophobic Antifogging Coatings for Optical Sensors

Transparent substrates are widely used for optical applications from lenses for personal and sports eyewear to transparent displays and sensors. While these substrates require excellent optical properties, they often suffer from a variety of environmental challenges such as excessive fogging and surface contamination. In this work, it is demonstrated that a wet‐style superhydrophobic coating, which simultaneously exhibits antifogging, antireflective, and self‐cleaning properties, can be prepared by pattern transferring low‐surface‐energy microstructures onto a heterostructured nanoscale thin film comprising polymers and silica nanoparticles. The polymer–silica nanocomposite base layer serves as a hydrophilic reservoir, guiding the water molecules to preferentially condense into this underlying region and suppress reflection, while the low‐surface‐energy microstructure enables contaminants adsorbed on the surface to be easily removed by rinsing with water. Wet‐style superhydrophobic antifogging coatings that exhibit superhydrophobicity and self‐cleaning properties are prepared by pattern transferring low‐surface‐energy micropillars on a polymer–silica nanocomposite. The polymer–silica nanocomposite allows the coating to simultaneously maintain an excellent optical property in fogging conditions by preferentially guiding the water vapor to condense into this underlying hydrophilic reservoir.