Water, proton and gas transport properties are of paramount importance in the performance of membranes in fuel cell applications. Currently there is not satisfactory understanding of the interplay between water/proton transport and the membrane performance. A key role is played by short side chains which characterise the structure of these ionomers. As matter of fact membranes at similar degrees of hydration but with different side chain length exhibit substantially different proton mobilities. The employment of new technologies enables fundamental scientific knowledge to go beyond the limits of the current membranes. In this framework HICOS project has as object to contribute to solve this scientific question. The project benefits of a novel technique, named plasma radical assisted polymerization via chemical vapour deposition to deposit new tailored high performance membranes. One of the foressen benefit of the project will be the direct deposition of membranes on the electrodes which compose the membrane electrode assembly, the core of the fuel cell, making the process quicker and cheaper compared to the conventional one. As relevant scientific outputs of this project, novel membranes with tuneable properties will be delivered in a demonstrator.