While the weather here in the UK is quite pleasant at the moment we’re never going to corner the market in solar energy production, so until they figure out how to make power from the rain, maybe we should look at the next best thing, puddles, or specifically the evaporation of water from them.

A team at Columbia University, have come up with the world’s first evaporation-driven engine, creating power from a small pool of water that evaporates at room temperature and it uses living organisms to do so. The teams leader, Ozgur Sahin, first noticed that certain types of bacterial spores reacted to the presence or absence of moisture by expanding and contracting. Together with the team he has used this to create a new material they call HYDRAs (HYgroscopy-DRiven Artificial muscles).

These are placed in and enclosure over a small pool of water, which, as it evaporates raises the humidity in the enclosure causing the HYDRAs to expand this in turn pulls on a small electromagnetic generator which converts the movement into energy. the movement also opens a set of shutters, lowing the humidity and causing the HYDRAs to contract, close the shutters and start the whole process again.

Currently the energy generated isn’t anything to write home about, roughly 50 microwatts from each pull cycle, but that’s energy from a puddle of water that’s doing nothing but just sitting there at room temperature. Sahin says that the current HYDRAs are only using about 1% of the potential enegy that the spores could generate and he’s already working on a new version that bumps that up to 33%. Sure it’s a long way from lighting and heating our homes (or even boiling a kettle) but it’s a simple, low cost, endlessly renewable source of power if it can be scaled up. Will that ever happen? If you believe this almost Apple-like video the team made, this technology is the future.

Source: Popular Mechanics Image Source: ExtremeBio Via YouTube