Scientists Build a Battery You Can Power With Your Spit

When you're all out of options, there's one resource left in your mouth.

saliva test
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You're stranded in the middle of nowhere, phone battery dead. Lacking all access to electricity or even solar power, you turn to your last resource—your own spit. That's the dream of researchers at Binghamton University in upstate New York, who have developed a battery that can be powered by saliva.

The development is the next step in microbial fuel cells (MFCs), which drive electrical currents through bacteria. Binghamton Electrical and Computer Science Assistant Professor Seokheun Choi has been focused on creating small power sources for healthcare devices in rural regions which might not have the constant supply of electricity that urban areas do.

"On-demand micro-power generation is required especially for point-of-care diagnostic applications in developing countries," says Choi in a press statement. "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."

The new bacteria-powered batteries are paper-based. They build MFCs with inactive, freeze-dried cells that have the ability to send electricity outside of their cell walls, which are referred to as exoelectrogenic. These exoelectrogenic cells are made wet through saliva, which wakes up their ability to generate power within minutes.

The next step for Choi's spit-powered battery, developed with research assistant Maedeh Mohammadifar, is to improve its power density, getting more wattage per square inch. That'll be an important step towards real-world applications.


So while your spit won't power your phone battery any time soon, once it can power one LED light, it will stand to reason that it can be made to power several more.

Source: Binghamton

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