No matter how much we learn about nature, there are still some surprises out there. Like these naturally occurring microbes that can convert sewage water into electricity.
A team at Stanford University has developed a new system that uses these "wired microbes" as mini power plants: they consume sewage and produce electrons, which are then captured by a battery and converted into electricity.
Over the past dozen or so years, other teams have tried to harness electricity from these microbes, with limited success. The current project harnesses about a third of the wastewater's energy potential, a big improvement over past efforts.
It may be more efficient, but the new approach is also costly: it uses silver oxide, an expensive material, to harness the microbes' electrons. The team says it's currently searching for alternatives.
"We demonstrated the principle using silver oxide, but silver is too expensive for use at large scale," said Yi Cui, one of the study's authors. "Though the search is underway for a more practical material, finding a substitute will take time."
The prototype system is small — about the size of a D-cell battery — and uses two electrodes to capture the energy that the microbes give off. If they succeed in finding a cheaper way to harness the electricity, the plan is to go much bigger, and use the microbes in places like sewage treatment plants or in "dead zones" in coastal waters or lakes where pollution has damaged marine life.
This only one recent story about work that blurs the line between nature and human technology: check out this researcher who's making organs with built-in electronics, this insect with naturally occurring gears in its legs, and this team that's coating spider silk with carbon nanotubes so it can conduct electricity.
Via Ars Technica