Even though direct methanol fuel cells (DMFCs) were developed to support power needs, there are still unresolved drawbacks. The main focus of this research is the membrane electrode assembly (MEA), which is the most important component of the fuel cell. The MEA consists of a combination of the diffusion layer, the electrode layer and a membrane. Several obstacles may interfere with the functioning of the MEA, including its relatively low anode electro-catalytic activity, methanol crossover and mass transport. In this paper, an overview of the layer and engineering challenges associated with the MEA will be presented in detail. This paper will also discuss the materials while focusing on the current problems, structure layers, morphologies and fabrication methods of MEAs in DMFCs.