This Battery Is Powered By Your Own Spit


Jonathan O'Callaghan

Senior Staff Writer


A picture of the battery. Seokheun Choi

Researchers have created a battery that is activated by your spit, which could lead to cleaner sources of energy in the future.

Carried out by Binghamton University in New York, the study was published in the journal Advanced Materials Technologies.


The paper-based battery is powered by bacteria, using microbial fuels cells combined with freeze-dried exoelectrogenic cells. These are microorganisms that transfer electrons outside their cells.

Within minutes of adding power, these cells generated power. With a power density of a few microwatts per centimeter square, 16 of the microbial fuel cells connected together powered a light-emitting diode (LED) for 20 minutes.

"On-demand micro-power generation is required especially for point-of-care diagnostic applications in developing countries," said co-author Professor Seokheun Choi in a 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 batteries could be shaped in different ways, including folded like sheets or shaped like a ninja star. Aside from spit, they were also able to generate power with a drop of dirty water.

Professor Seokheun Choi, who conducted the research. Binghamton University, State University of New York

“This work creates a low-cost, disposable, long shelf life and eco-friendly micropower source that can be easily integrated in paper-based POC [point-of-care] devices,” the abstract of the paper states. It adds that it can be “readily activated by one drop of saliva, which is readily available in any challenging area.”

Before it can be truly useful, Choi said they needed to get the power up to hundreds of milliwatts of energy. However, it’s certainly a promising technology, and who knows, maybe one day in the near future our electric cars will be powered by spit. Over to you, Elon Musk.

This isn’t the only battery news we’ve had recently. In February, we learned that a battery that could last for 10 years was being developed. In June, scientists created a phone that works without any battery at all, using radio waves to power the device.

If we can get clean and powerful batteries, then it’s a good step towards breaking our reliance on fossil fuels. Here’s hoping for some more breakthroughs in the future.

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