A simpler and more efficient MFC can be made by omitting the cathode chamber and placing the cathode electrode directly onto the proton exchange membrane (PEM). Single chamber MFC avoids the need to aerate water because the oxygen in air can be directly transferred to the cathode. It offer simpler designs and cost savings.
Single-chambered MFCs are quite attractive for increasing the power output because they can be run without artificial aeration in an open air cathode systems and can reduce the internal ohmic resistance by avoiding the use of a catholyte as a result of combining two chambers.
Graphite rods were placed inside the anode chamber and these rods extended outside of the anode chamber and were connected to the cathode via an external circuit.