Improvement of under‐the‐rib oxygen concentration and water removal in proton exchange membrane fuel cells through three‐dimensional metal printed novel flow fields. - Chen, Gaojian; Shi, Weidong; Xuan, Jin; Penga, Željko; Xu, Qian; Guo, Hang; Su, Huaneng; Xing, Lei (AIChE Journal, 2022)