Anyone who’s ever made his or her own beer knows that fermentation produces energy. So it was just a matter of time before someone decided to harness that energy and put it to good use.
Engineers at Purdue University have developed a tiny medical pump that simply needs yeast (everyday baker’s yeast will do), sugar, water, and the heat from a person’s body in order to function. No electricity is required. When the yeast eats the sugar, it produces carbon dioxide gas (you might call them "yeast farts") and this powers the micropump, whose purpose is to pump drugs into the body.
As the researchers point out, yeast has a long shelf life, even under extreme conditions of varying temperatures and humidity levels. And, since the length of fermentation can be easily controlled over a specified amount of time, so can the allocation of drugs. In addition, the microorganism technique could help make pumps less bulky since they wouldn’t require batteries.
Considering how far back the origins of fermentation date, this is quite an ancient fix to a modern problem—so it’s probably making a lot of other engineers and designers ask why they didn’t think of it first.