NOVELTY - A bioanode (A1) comprises: (a) an electron conductor; (b) at least one anode enzyme that can react with oxidized form of electron mediator (M1) and a fuel fluid to produce oxidized form of the fuel fluid and a reduced form of (M1), where the reduced form of (M1) releases electrons to the electron conductor; and (c) an enzyme immobilization material which is permeable to fuel fluid and (M1); where the macroscopic shape of the bioanode is non-planar and the surface area of the bioanode is greater than that of otherwise identical macroscopically planar bioanode.    USE - As bioanode and biocathode electrodes for the producing biofuel cells (claimed), useful for generating electricity via enzyme mediated redox reactions.    ADVANTAGE - The non-planar macroscopic shape of the biocathode or bioanode has an electrode area of at least 2-15 times greater than an otherwise identical biocathode or bioanode having a planar macroscopic shape.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a biocathode (C1) comprising: (a) an electron conductor; (b) at least one cathode enzyme capable of reacting with a reduced form of an electron mediator (M1) and an oxidant to produce an oxidized form of (M1) and water; and (c) an enzyme immobilization material comprising (M1), where the enzyme immobilization material is permeable to the oxidant, an oxidized form of (M1) can gain electrons from the electron conductor to produce a reduced form of (M1); and where the macroscopic shape of the biocathode is non-planar and increases the surface area of the biocathode relative to a macroscopically planar biocathode;    (2) a biofuel cell for generating electricity comprising: a fuel fluid; an electron mediator; the bioanode (A1); and the biocathode (C1), where the bioanode and biocathode are separated by a porous insulating material; and    (3) generating electricity using the biofuel cell involving: (a) oxidizing the fuel fluid at the bioanode and reducing the oxidant at the biocathode; (b) oxidizing the reduced form of the electron mediator during the reduction of the oxidant at the biocathode; and (c) either oxidizing and reducing the electrocatalyst at the electron conductor; or reducing the electron mediator at the electron conductor.