CNET también está disponible en español.

Ir a español

Don't show this again

Sci-Tech

Wet Wheels: A toy car powered by evaporating water

Columbia University researchers discover a new source of alternative energy by harnessing the power of evaporation and soil bacteria spores.

toy-car.jpg
Scientists at Columbia University created a tiny car that runs on evaporation by using spores from soil bacteria. Video screenshot by Danny Gallagher/CNET

When you hear the terms "renewable energy" or "alternative energy," images of wind farms, biofuels or Ed Begley Jr. on a solar-powered golf cart might jump to mind. While terms like "evaporation" and "evaporated water" might not make your list, a new study from New York's Columbia University could help push them into the alternative-energy-source column.

Using evaporated water, a Columbia team created engines that can power small devices like a toy car and a flashing LED lamp. The rudimentary engines "generate rotary and piston-like linear motion using specially designed, biologically based artificial muscles responsive to moisture fluctuations," according to an abstract for a study on the work published Tuesday in the journal Nature Communications.

The scientists were inspired to make evaporation-powered devices thanks to a spore found in soil bacteria that reacts to moisture by expanding and contracting, according to a video released by Columbia University in conjunction with the study.

When this spore encounters moisture, "it absorbs some of the moisture and it gets bigger and when it finds a dry environment again, it shrinks again," Ozgur Sahin, an associate professor of biological sciences, says in the video. "This is very similar to a muscle movement...We worked on bacteria spores for quite a while until this idea struck that their mechanical properties can be useful technology."

The team put the spores on strips of tape and designed small devices that could be powered by the tape's muscle-like movements. The gadgets included a light source, and a miniature car (weighing less than a quarter of a kilogram) that moves forward as the water in the car evaporates.

The video below shows the car in motion using this evaporation technology. Of course, we're still a long way off from having a full-size vehicle that can transport people using the evaporated water in our atmosphere. However, if we reach that day, I just have one request. Can we come up with a less wimpy name for it than the Leaf or the Prius? How about something with teeth like the Vapor-Jaguar or the Muscle?

(Via The Guardian)