Researchers from State University of New York, Binghamton developed paper-made battery that is powered by bacteria
Paper as a material has efficient bio-sensing ability and is inexpensive, disposable, and flexible and has a high surface area. However, complex sensors require a power supply. Conventional batteries are expensive and cannot be used with paper substrates. Now, a research led by Seokheun (Sean) Choi, Ph.D developed a paper-based bio battery to power sensors. The research was presented at the 256th National Meeting & Exposition of the American Chemical Society on August 19, 2018. The team achieved the breakthrough from previously developed disposable paper-based biosensors used for diagnosis of diseases and health conditions. Although, the bio-sensors rely on color changes to report a result, they are not highly sensitive as the biosensors need a power supply to boost sensitivity.
The current research used thin layers of metals and other materials that were printed on the paper surface. Exoelectrogens were then freeze- dried and applied on the paper. Exoelectrogens—are a class of bacteria that transfer electrons outside of their cells. Production of energy in the bacteria facilitate generation of electrons, which pass through the cell membrane. The electrons can contact with external electrodes to power the battery. The researchers added water or saliva to activate the battery. The liquid revived the bacteria within a couple of minutes and produced electrons that powered a light-emitting diode and a calculator. The effect of oxygen was analyzed on the performance of the bio-battery. Oxygen soaked up electrons produced by the bacteria, before the elections reach the electrode and decreased power generation. However, the decrease in power generation was minimal as the bacterial cells were tightly attached to the paper fibers. Such strong bond rapidly whisked the electrons away to the anode before oxygen could intervene. The paper battery currently has a shelf-life of about four months and can be used only once. The researchers are focused on improving the survival and performance of the freeze-dried bacteria to offer a longer shelf life for the battery.