Paper‐based electronics, or papertronics, are an emerging device platform valued for their low cost, flexibility Researchers harnessed bacteria to power these paper batteries. Source: Seokheun Choi, State University of New York, BinghamtonResearchers harnessed bacteria to power these paper batteries. Source: Seokheun Choi, State University of New York, Binghamtonand excellent mechanical, dielectrical and fluidic properties. Disposable paper-based biosensors for diagnosis of diseases and health conditions, as well as for detecting environmental pollutants, have already been developed.

Researchers at the State University of New York, Binghamton, sought to improve the power supply for these paper devices in order to enhance their sensitivity and broaden applications. After printing thin layers of metals and other materials onto a paper surface, freeze-dried exoelectrogens — bacteria that can transfer electrons outside of their cells — were applied to the paper. The transferred electrons make contact with external electrodes and power the battery, which is activated by the addition of water or saliva. The liquid revives the bacteria in a few minutes, enabling the microbes to supply sufficient electrons to power a light-emitting diode and a calculator.

The effect of oxygen on device performance was also analyzed, as oxygen could soak up electrons produced by the bacteria before reaching the electrode. Its presence slightly decreased power generation but the effect was observed to be minimal.

The paper battery can be used once and then discarded, and has a shelf-life of about four months. The team is now seeking to extend the survival of the freeze-dried bacteria in order to realize a longer shelf life, and has applied for a patent for the battery and is seeking industry partners for commercialization.

The findings were presented at the 256th National Meeting & Exposition of the American Chemical Society, and are published in Advanced Materials Technologies.

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