The objective of this proposal is to fabricate a low cost high performance hybrid inorganic/polymer membrane that has a proton area specific resistance (ASR) < 0.02 ohm cm2 at the operating temperature of an automotive fuel cell stack (95 - 120°C) at low inlet RH <50% with good mechanical and chemical durability. Additionally the membrane will be optimized for low hydrogen and oxygen crossover with high electrical ASR at all temperatures and adequate proton ASR at lower temperatures. We also seek to gain valuable insights into rapid proton transport at the limit of proton hydration. Additional research will be performed to incorporate the membrane into a 50 cm2 membrane electrode assembly (MEA). The materials at the start of this project are at a TRL of 2, as we have shown that they have proton conductivity under high and dry conditions, but we have not yet consistently shown that they will function in an operational fuel cell. At the project’s end the materials will be at a TRL of 4 and will be integrated into an MEA, demonstrating that they can function with electrodes as a single fuel cell.