Tiny biobattery with 100-year shelf life runs on bacteria

A tiny biobattery that could still work after 100 years has been developed by researchers at Binghamton University, State University of New York.

Last fall, Binghamton University Professor Seokheun “Sean” Choi and his Bioelectronics and Microsystems Laboratory published their research into an ingestible biobattery activated by the pH factor of the human intestine.

Choi and Ph.D. student Maryam Rezaie took what they learned and incorporated it into new ideas for use outside the body.

A new study in the journal Small, which covers nanotechnology, shares the results from using spore-forming bacteria similar to the previous ingestible version to create a device that potentially would still work after 100 years.

“The overall objective is to develop a microbial fuel cell that can be stored for a relatively long period without degradation of biocatalytic activity and also can be rapidly activated by absorbing moisture from the air,” says Choi, a faculty member in the Department of Electrical and Computer Engineering at the Thomas J. Watson College of Engineering and Applied Science.

“We wanted to make these biobatteries for portable, storable and on-demand power generation capabilities,” Choi says. “The problem is, how can we provide the long-term storage of bacteria until used? And if that’s possible, then how would you provide on-demand battery activation for rapid and easy power generation? And how would you improve the power?”

The dime-sized fuel cell was sealed with a piece of Kapton tape, a material that can withstand temperatures from -500°F to 750°F. When the tape was removed and moisture allowed in, the bacteria mixed with a chemical germinant that encouraged the microbes to produce spores. The energy from that reaction was enough to power an LED, a digital thermometer, or a small clock.

Heat activation of the bacterial spores cut the time to full power from 1 hour to 20 minutes, and increasing the humidity led to higher electrical output. After a week of storage at room temperature, there was only a 2% drop in power generation.

The study is funded by the Office of Naval Research, and it’s easy to imagine the military applications for a power source that could be deployed on the battlefield or in remote locations. However, there would be plenty of civilian uses for such a fuel cell, too.

While these are good results, Choi knows a fuel cell like this needs to power up more quickly and produce more voltage to become a viable alternative to traditional batteries.

“I think this is a good start,” he says. “Hopefully, we can make a commercial product using these ideas.”

Binghamton University
https://www.binghamton.edu