For a long time scientists have been experimenting with microbial fuel cells and finding new applications for them. A microbial fuel cell uses the electrons that are released from bacteria as they feed on organic waste to produce electricity.
Researchers from Binghampton University have found a way to house that process in a foldable, paper-based battery. The small paper construction means that the battery can be paired with low-power biosensors and safely disposed of when its job is done. It can also be made for pennies.
It's especially well suited for environmental sensing or medical applications because it can produce power wherever microbes are present like water, soil or the human body.
The lead researcher on the project, Assistant Professor and Director of the Bioelectronics & Microsystems Lab Seokheun "Sean" Choi, built the device by creating an anode on one side of the paper that consisted of a reservoir of bacteria-filled water made out of a conductive polymer. A small amount of silver nitrate encased in a thin layer of wax acts as the cathode on the other end of the paper.
The paper can then be folded origami-style to produce an electric current. Different folds create different levels of output with an accordion fold generating the most electricity.
We previously wrote about Choi's work on origami paper batteries, but this new work is a majorly improved version.
"This one is much more upgraded. You don't need to use many paper layers. All the components will be integrated into one sheet of paper," Choi told Seeker. "Now, this work uses wastewater, but the devices can be workable with any liquid like body fluids, such as blood, sweat, urine, or saliva."
The paper battery could be used in disaster relief, on battlefields or in medical clinics in remote areas -- anywhere that low-power devices need electricity and microbes are present. They could also be used to detect pathogens and toxins in the environment.