A disposable water-activated paper-based MFC using dry E. coli biofilm.

Highlights • We develop a novel portable and disposable paper-based biobattery. • Our biobattery is on-demand electricity generation activated by a drop of tap water. • A low-cost, simple-structure battery case is created by single layer of paper filter. • We proposed integrated air-cathode paper-based proton exchange membrane. • Proposed battery can be used for paper-based diagnostic devices. Abstract A novel, portable, and disposable paper-based microbial fuel cells (MFC) generating electricity from harmless strain of Escherichia coli (E. coli) has been developed. This MFC is on-demand electricity generation activated by a drop of tap water in a dry anode containing the biofilm of E. coli. A low-cost, simple-structure MFC case was created by a single layer of paper filter with high order of folding, which could support interchangeable dry bacteria-loaded anodes. The paper filter was innovatively engineered to make an integrated air-cathode proton exchange membrane (ACPEM) by coating carbon nanotube mixed with potassium ferricyanide on one surface and spraying hydrophobic solution on the other surface, respectively. The E. coli biofilm pre-inoculated in the anodes made of activated carbon sheet was simply dried in the air for the sake of long-term storage and usage. The dry anodes can be simply set in the MFC case with the readily prepared ACPEM, which can be used for on-demand power generation within seconds after adding water with maximum power density of 8.8μW/cm2. [ABSTRACT FROM AUTHOR]