Diversifying our energy sources is key to reducing our dependence on fossil fuels, and a fascinating possibility is to use bacteria that generate electricity. The engineers of the Binghamton University have created a three-layered bacterial biobattery: it contains several species of bacteria that absorb sunlight and generate electricity.
The research was published in the Journal of Power Sources (and I link it here).
Bacterial energy
The biobattery comes from a long series of Professor's projects Seokheun Choi, which has been experimenting with bacteria-based paper batteries for years. He gave them the most disparate shapes: from boxes to stars. Only one problem, common to all his creations: the short duration.
To increase the longevity of his bacterial batteries, Choi came up with the classic “Unity is strength”. By creating bacterial biobatteries that combine multiple species capable of "helping" each other, the researcher immediately improved performance.
How does the system work?
The researchers arranged three layers of chambers with distinct bacteria. The upper layer hosted photosynthetic bacteria. This bacterial section absorbs energy from sunlight and produces organic molecules that power the “middle floor”.
The intermediate bacterial section works a bit like a "filter": it absorbs nourishment from the upper sector, enriches it with some chemical substances and then 'discards' it in favor of the "bottom floor".
There is nothing to be done: everywhere in history it seems that the hardest work falls at the bottom of the pyramid: the electricity is generated by the bacteria in the lower layer, fueled by the process that takes place "at the top".
Next steps
Choi says he is satisfied with the longevity obtained: the bacterial battery lasts for weeks. Now we need to make sure it's useful for something, though. To do this, the first thing to solve is the permeability of the paper: future versions of the battery must at least be able to float!
Its long-term ambition, however, is to make it capable of floating on water and self-healing if damaged. We'll see.
