A team of Columbia University scientists have done what seems like the impossible: turn room-temperature water into energy. For the whole story, we encourage you to head over to Popular Mechanics. Here’s a brief rundown.
The breakthrough comes via a new biomaterial developed by Columbia professor Ozgur Sahin that makes the collection of energy from water possible.
The key to Sahin’s astonishing new invention is a new material that Sahin calls HYDRAs (short for hygroscopy-driven artificial muscles). HYDRAs are essentially thin, muscle-like plastic bands that contract and expand with tiny changes in humidity. A pinky finger-length HYDRA band can cycle through contraction and expansion more than a million times with only a slight, and almost negligible, degradation of the material. “And HYDRAs change shape in really quite a dramatic way: they can almost quadruple in length,” Sahin says.
The idea for the HYDRA material came to Sahin more than half a decade ago, when he came across an unusual find in nature. While studying the physical properties of micro-organisms with advanced imaging techniques, he discovered that the spore of the very common grass bacillus bacteria responds in a strange way to tiny amounts of moisture. Although the dormant spore has almost no metabolic activity and does no physical work, its outer shell can soak up and exude ambient levels of evaporated water—expanding and shrinking while doing so.
“The spores stay very rigid as they expand and contract in response to humidity,” Sahin says. “That rigidity means their movements come with a whole lot of energy.”
By enclosing these HYDRAs over a puddle of water, the evaporation that occurs naturally can cause them to shrink and expand, creating energy. So far it’s not all that much energy, as each pull of the HYDRAs only generates about 50 microwatts, but with warmer water, the system is much more effective.
Ozgur’s team built a secondary HYDRA-powered system that runs a turbine powered only by evaporating water.
Unfortunately, a version of this system that could power your home or replace your gas-guzzler is probably still a long ways off, but clean energy systems like this are undoubtedly the future.