A biological fuel cell microfabricated within a single sheet of paper

Abstract

We report a novel technique for fabricating microbial fuel cells (MFCs) within a single sheet of paper, which greatly (i) reduces fabrication cost/processes of the fuel cell devices and (ii) revolutionizes their mass production for the potential use as a disposable battery in resource limited settings. A number of device units were simply batch-fabricated on a flexible/scalable single sheet of paper by spraying/screen-printing electrode materials and forming hydrophilic regions with hydrophobic wax. A 3-D MFC structure was created by forming four functional layers of an anode, a hydrophilic reservoir, a hydrophobic wax-based ion exchange membrane, and an air-cathode in a single sheet of chromatography paper. Upon adding one drop of bacteria-containing liquid onto the device, the hydrophilic reservoir allowed for rapid bacterial cell attachment to the electrode, where bacterial respiration then transferred electrons from the organic liquid to the electrode, generating power to an external load.