Production technology and applications of honeycomb films

“Breath figure formation” during the casting process of polymer solutions under high atmospheric humidity provides honeycomb-patterned polymer films (honeycomb films) with regularly arranged micropores. The development of production technology for large-area honeycomb films is indispensable for their various applications. Manufacturing equipment consisting of three zones (for casting, humidification, and drying of polymer solutions) for successive formation of large-area honeycomb films was newly designed and constructed. By using this equipment, physicochemical experimental parameters, e.g., the surface temperature of polymer solutions, dew point of the humidification zone, humidification time, and interfacial tension between water and the polymer solution, were effectively changed to optimize the density and size of condensed water droplets. Large-area honeycomb films were formed by a roll-to-roll process. Herein, recent developments in biomedical applications of honeycomb films are described.