Abstract: The present disclosure relates to a membrane electrode assembly including: a polymer electrolyte membrane; an anode catalyst layer formed on one side of the polymer electrolyte membrane; a cathode catalyst layer formed on the other side of the polymer electrolyte membrane; and a porous carbon layer formed on the cathode catalyst layer on the side opposite to the side contacting with the polymer electrolyte membrane and comprising a polymer binder and a carbon particle, and a fuel cell including the same. The present disclosure can prevent water evaporation from an electrolyte under low-humidity environment while minimizing decrease in performance under high-humidity operating environment and can improve fuel cell performance by facilitating the back diffusion of water generated at the cathode.

Abstract: The present invention provides a hierarchical microstructure having nanopatterns formed on an upper surface as well as a side surface thereof, so as to maximize the effect of a multiscale structure. Therefore, the hierarchical microstructure can have a wider surface area. Also, the present invention provides a method of preparing a mold for forming the hierarchical microstructure using a sequential imprinting procedure and a creep behavior. According to the present invention, the mold for forming a hierarchical microstructure can be prepared more effectively and easily.