Spit-powered microbial fuel cell developed to power biosensors in remote regions
A microbial fuel cell (MFC) that generates power by using energy from microbes in spit or dirty water has been designed by Binghamton University researchers in the State of New York.
The battery is designed to be used in extreme conditions where normal batteries don’t function and although it only generates a relatively small amount of electricity, it is enough to power devices such as biosensors.
Professor Seokheun Choi, who developed the battery, has been focusing on developing micro-power sources for use in resource-limited regions to power point-of-care (POC) diagnostic biosensors. Choi has already created several paper-based, bacteria-powered batteries.
“On-demand micro-power generation is required, especially for point-of-care diagnostic applications in developing countries,” said 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.”
Choi, along with research assistant Maedeh Mohammadifar, created a high-performance, paper-based, bacteria-powered battery by building microbial fuel cells with inactive, freeze-dried exoelectrogenic cells, which generate power within minutes of adding saliva.
The battery generated reliable power from one drop of saliva, supplying on-board power that could be used by the next generation of disposable, paper-based POC diagnostic platforms.
“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,” wrote the researchers.
Choi is now focused on trying to improve the battery’s power density so that more applications can make use of it.
“Now, our power density is about a few microwatts per centimetre 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,” said Choi.
In October, Cambridge University researchers demonstrated a lithium-sulphur battery which had a design that took inspiration from the cells lining the human intestine.