Running water creates electricity at 10 times the intensity than previously thought, according to new Australian research.
Scientists at RMIT University and the University of Melbourne found when a water droplet became stuck on a surface, the force built up until it “jumped or slipped” past the obstacle, created an irreversible charge that had not been reported before.
RMIT’s Peter Sherrell said the new understanding of this “stick-slip” motion of water over a surface paved the way for surface design with controlled electrification.
Dr Sherrell said potential applications ranged from improving safety in fuel-holding systems to boosting energy storage and charging rates.
“Most people would observe that rainwater drips down a window or a car windscreen in a haphazard way, but would be unaware that it generates a tiny bit of electrical charge,” he said.
“Previously, scientists have understood this phenomenon as occurring when the liquid leaves a surface, which goes from wet to dry.
“In this work we have shown that charge can be created when the liquid first contacts the surface, when it goes from dry to wet, and is 10 times stronger than wet-to-dry charging.”
Dr Sherrell said another important finding was that charge did not disappear.
“Our research did not pinpoint exactly where this charge resides, but clearly shows that it is generated at the interface and is probably retained in the droplet as it moves over the surface.”
Read the full study: Irreversible Charging Caused by Energy Dissipation from Depinning of Droplets on Polymer Surfaces.
