A method of designing a fuel cell includes executing one or more programs on one or more computing devices having one or more processors to predict a location of one or more liquid regions and one or more vapor regions in microchannels at an air layer of a plate of the fuel cell. Based on the prediction, fluid flow networks for the air layer, a hydrogen layer, and a coolant layer of the fuel cell are simultaneously optimized via homogenized flow optimization. In response to the results of the homogenized flow optimization, one or more multi-scale Turing-patterned microstructures are generated for the air layer and the hydrogen layer. One or more multi-scale Turing-patterned microstructures are generated for the coolant layer by stacking the air layer and the hydrogen layer.