A team of researchers from Columbia University harnessed the power of evaporation to drive the two new devices.
The first is a floating piston-driven engine that is capable of powering a flashlight, and the second is a rotary engine used to power a miniature car. The motors mark the first time that scientists have used evaporation as a source of energy.
Evaporation used to power devices
Lead study author Ozgur Sahin, an associate professor of biological sciences and physics at Columbia University, said, “Water in nature is in constant transformation. We want to capture energy from evaporation. That process is very powerful, we haven’t been able to harness it until now.”
“Evaporation is a ubiquitous phenomenon in the natural environment and a dominant form of energy transfer in the Earth’s climate. Engineered systems rarely, if ever, use evaporation as a source of energy, despite myriad examples of such adaptations in the biological world. Here, we report evaporation-driven engines that can power common tasks like locomotion and electricity generation,” he added.
The engine is powered by evaporation from bacterial spores which expand and contract depending on the level of humidity.
A previous paper showed the potential of the spores to generate energy, and now this power has been harnessed by gathering a concentration of the spores to create an artificial muscle which can produce energy when humidity levels are changed.
The movement of the engine generated enough electricity to power a flashlight, and was also used in a turbine engine which used the spores to power a car.
Great potential for uses of the technology
Future developments in the field may include a spore-driven machine that can operate more autonomously when they are near a source of water. The scientists believe that the technology could demonstrate many more applications in the future, including artificial muscle for robots.
Sources of evaporation are common in nature, and the materials required to build the devices are relatively inexpensive, meaning that the technology could also be used to power devices in remote locations.
The team behind the innovation admit that such applications may still be a few years away, but the harnessing of such a common phenomenon to create energy is an exciting development.