Enzymatic Biofuel Cell

An enzymatic biofuel cell is a specific type of fuel cell that uses enzymes rather than precious-metal catalysts such as platinum to oxidize its fuel. The enzymes strip electrons from fuel molecules and force them through an external wire around an electrolyte barrier to generate current, either transferring electrons directly to the electrode or passing them through chemical mediators, and because the enzymes must be immobilized near the anode and cathode to work, an unimmobilized enzyme lets most of its liberated electrons diffuse away before they reach an electrode. The cells run on organic fuels such as sugars and alcohols, which are abundant and inexpensive compared with the refined metals conventional fuel cells require.