A method of creating a polymer surface with surface structures is disclosed. The method includes creating a mold, forming a metal sheet into the molds, creating a surface structure on a surface of the metal sheet by exposing the surface to laser pulses, and bringing a curable polymer to be in contact with the surface of the metal sheet containing the surface structure, curing the curable polymer, and separating the cured polymer from the metal sheet, resulting in a polymer surface containing the surface structure. The polymer surfaces with the surface structures can be hydrophobic or superhydrophobic depending on the micro and nano features contained by the surface structures.

A method of manufacturing a photothermal conversion element includes preparing a solid material and forming a processed region processed by irradiation of the solid material with a laser beam. The forming includes grain refining the solid material to blacken the processed region.