Here comes a Paper Battery powered by Bacteria

Batteries. Don’t we constantly need them to power all those seemingly indispensable gadgets in our lives? The trouble, of course, is that most of them tend to contain plenty of toxic substances… and that they don’t last all that long so they invariably end up on trash heaps, thereby posing constant hazards to the environment.

Luckily, the race is on to produce so-called bio-batteries – ones that use organic compounds to store power. And bio-batteries just keep on getting better and simpler.

To wit: Researchers at Binghamton University, in New York, have devised a bacteria-powered battery on a single sheet of paper. Their invention can power disposable electronics and its simple design makes it ease to reproduce, which, the researchers explain in a press release, “could revolutionize the use of bio-batteries as a power source in remote, dangerous and resource-limited areas.”

The invention falls within the field of “papertronics,” a new area of paper-based research that seeks to merge paper and electronics. The idea is to create useable and disposable electronics that could be reproduced with ease from materials that are readily available everywhere on earth.

“Papertronics have recently emerged as a simple and low-cost way to power disposable point-of-care diagnostic sensors,” explains Assistant Professor Seokheun “Sean” Choi, who is director of the Bioelectronics and Microsystems Lab at the university. “Stand-alone and self-sustained, paper-based, point-of-care devices are essential to providing effective and life-saving treatments in resource-limited settings,” he added, referring to remote areas of the world where conventional batteries are hard to come by.

To create a cathode, Choi and one of his colleagues have affixed a ribbon of silver nitrate under a thin layer of wax on one half of a piece of chromatography paper. They proceeded to create a reservoir out of a conductive polymer on the paper’s other half, which acted as the anode. They then folded the paper and added a few drops of bacteria-filled liquid so that the microbes’ cellular respiration can power the battery.

“The device requires layers to include components, such as the anode, cathode and PEM (proton exchange membrane),” Choi said. “[The final battery] demands manual assembly, and there are potential issues such as misalignment of paper layers and vertical discontinuity between layers, which ultimately decrease power generation.”

Different folding and stacking methods can change and improve power and current outputs, explain the scientists, who managed to generate 31.51 microwatts at 125.53 microamps with six batteries in three parallel series and 44.85 microwatts at 105.89 microamps in a 6×6 configuration. “It would take millions of paper batteries to power a common 40-watt light bulb, but on the battlefield or in a disaster situation, usability and portability is paramount,” they explain. However, their battery can produce enough power to run biosensors that monitor glucose levels in diabetes patients or detect harmful pathogens.

“Among many flexible and integrative paper-based batteries with a large upside, paper-based microbial fuel cell technology is arguably the most underdeveloped,” Choi said. “We are excited about this because microorganisms can harvest electrical power from any type of biodegradable source, like wastewater, that is readily available. I believe this type of paper biobattery can be a future power source for papertronics.”