Saliva-powered battery that can be used in unusual conditions

Researchers at Binghamton University have developed a peculiar kind of 'microbial fuel cell', a battery that uses saliva as it source of power. It can be used unusual conditions where normal batteries tend to fail.

This remarkable invention is a result five years of research work by Professor Seokheun Choi, who has created several paper-based bacteria-powered batteries. He's been developing micro-power sources for point-of-care (POC) diagnostic biosensors.

"On-demand micro-power generation is required especially for point-of-care diagnostic applications in developing countries”, explains Professor Choi.

"Typically, those applications require only several tens of microwatt-level power for several minutes, but commercial batteries or other energy harvesting technologies are too expensive and over-qualified. Also, they pose environmental pollution issues.", he further added.

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Choi, along with research assistant Maedeh Mohammadifar created a paper-based, bacteria-powered battery that works on microbial fuel cells containing freeze-dried exoelectrogenic cells, which generates power as soon as it comes in contact with saliva.

"The proposed battery has competitive advantages over other conventional power solutions because the biological fluid for on-demand battery activation is readily available even in the most resource-constrained settings, and the freeze-drying technology enables long-term storage of cells without degradation or denaturation", researchers said.

For Choi increasing the power capacity is the main priority, "Now, our power density is about a few microwatts per centimeter square. Although 16 microbial fuel cells connected in a series on a single sheet of paper  generated desired values of electrical current and voltage to power a light-emitting diode (LED), further power improvement is required for other electronic applications demanding hundreds of milliwatts of energy".