The team has created a floating, piston-driven engine that generated electricity to power a flashing light and a rotary engine that drives a miniature car.
Ozgur Sahin, an associate professor of biological sciences and physics at the Columbia University and the lead author of the study 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.”
The Columbia University bioengineer added, “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, “Using these engines, we demonstrate an electricity generator that rests on water while harvesting its evaporation to power a light source, and a miniature car that moves forward as the water in the car evaporates.”
The power that propels the two engines is derived from evaporation via unique bacterial spores which expand and contract as humidity levels fluctuate.
Last year, researchers demonstrated the spores strength and potential, and now they’ve strategically applied concentration of spores to create a sort of artificial muscle that can be manipulated by changing humidity. The movement of the floating muscle like engine was able to generate enough electricity to power a small light.
The technology was similarly applied to create a wheel like turbine engine, using the mechanical energy stored in the spore-tipped turbine to power a car.
This is only the beginning of the technology. Scientists are now speculating that the use of spore muscles could become normal autonomous machine which can operate efficiently when they are near water. According to them machines can be developed to address various previous difficult obstacles and become more and more efficient.
Engine driven by evaporation could find new applications in powering robotic systems, sensors, devices and can also be put into machines which function in the natural environment.