A novel solution casting method of membrane preparation is explored to improve the conductivity of proton exchange membranes (PEMs). A high voltage alternative electric field is applied to a heterogeneous Nafion solution while evaporating the solvents, leaving aligned proton channels in the solidified membrane, and SAXS and WAXS have been given as direct evidences. Therefore, the trans-plane conductivity of the PEM is increased. A Non-solvent of low polarity carbon tetrachloride (CCl4) causes phase separation in the casting solution, which facilitates the Nafion ionomer to respond to the applied electric field. Despite the severe phase separation in the casting solution, the resultant electro-casting membrane shows a higher mechanical strength than that of the normal recast Nafion membrane. (C) 2013 Elsevier B.V. All rights reserved.