A method of making a fan having one or more dust-resistant surfaces comprises the steps of: providing (S50) an open mold for injection-molding purposes, having a cavity (43) corresponding to the desired configuration of fan components to be formed; wetting (S52) the surface of the cavity (43) with a mixture (24) of nanoparticles (19) and a solvent carrier; evaporating (S54) said solvent carrier, thereby depositing said nanoparticles on the wall of the cavity (43); closing (S56) the injection mold (10, 12); injecting (S58) thermoplastic (42) into the cavity (43); permitting the thermoplastic to harden, thereby binding the nanoparticles into the surface of the thus-created component(s), and removing (S60) the completed component(s) from the mold, for subsequent assembly as part of a fan.