Applied and Environmental Science

New Microbial Fuel Cell Battery is Activated by Spit

The next step in microbial fuel cells is a battery that is activated by saliva so it can be used in extreme conditions where normal batteries don’t function.  The device was developed at the State University of New York at Binghamton by Seokheun Choi, Maedeh Mohammadifar, and their colleagues.

Choi has spent the last five years developing micro-power sources that can be used in poor countries to power point-of-care diagnostic biosensors, and has created several paper-based, bacteria-powered batteries to do the job.

“On-demand micro-power generation is required…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 overqualified.  Also, they pose environmental pollution issues.”

Choi and Mohammadifar created a high-performance, paper-based, bacteria-powered battery by building microbial fuel cells with inactive, freeze-dried exoelectrogenic cells that produce power within minutes of adding only one drop of saliva.

The authors explained that 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 [fuel cell] storage without degradation or denaturation.

“Now our power density is about a few microwatts per square centimeter,” Choi said.  “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.”

For more information, go to the July 20 issue of Advanced Materials Technologies; DOI: 10.1002/admt.201700127.

Original article can be found here.