In this, the electrolyte is a polymer membrane coated with platinum, a metal that acts as a catalyst for the chemistry involved.

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Fuel cells come in several varieties, but the heart of the sort developed by Ballard is a polymer membrane coated on either side with platinum electrodes (the platinum also acts as a catalyst).

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The two electrodes, cathode and anode, are separated by a polymer electrolyte membrane which permits protons to cross to reach the cathode while the electrons are made to flow as part of a circuit to carry an electrical current.

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Statkraft isn't disclosing its secrets, except to say that its magic membrane is made of a polymer similar to plastic and extremely thin.

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The engineers used a silicone polymer to build a centimeter-long jellyfish consisting of a membrane with eight armlike appendages.

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