Diversifying our energy sources is a key part of reducing our reliance on fossil fuels, and one intriguing possibility is to tap into electricity-producing bacteria. Engineers at Binghamton University have now developed a biobattery that contains three layers of different bacteria species, which together take in sunlight and produce electricity.
This latest biobattery comes from a long line of projects by Binghamton Professor Seokheun Choi, who has been experimenting with bacteria-based paper batteries for years. These have taken the shape of matchbooks, ninja stars, accordion-folding paper, and even a stretchy wearable fabric. The bacteria commonly used for these devices generate electricity as a by-product of their respiration, feeding off nutrients in their environment, or even spit or sweat.
One downside they face, however, is longevity, so for the new study Choi set out to make longer-lasting biobatteries by combining multiple bacterial species that support each other.
The team stacked chambers containing distinct bacteria into three layers. The top layer housed photosynthetic bacteria that gained their energy from sunlight, producing organic molecules that feed the bugs in the lower layers. The bacteria in the bottom layer is the one that generates electricity from eating those nutrients, aided by some chemicals produced by the bacteria in the middle layer.
The team tested versions of these biobatteries that measured 3 cm2 (0.5 in2), and found that they could generate electricity for weeks at a time. That could make them useful for running small sensors or electronics in remote areas, without human supervision. The current version of the biobattery doesn’t produce a huge amount of electricity, but the team says the output could be increased by adding more units.
Choi says that work on future versions will focus on making them able to float on water and self-heal if damaged.
The research was published in the Journal of Power Sources.
Source: Binghamton University
