New research from the University of Edinburgh and the University of Warwick could have far reaching implications in a range of fields, from additive manufacturing to weather forecasting. The research in question sheds light onto the precise molecular mechanisms that cause drops of liquid merge together.
The UK-based research involved running molecular simulations on a supercomputer to analyze and understand interactions between the tiny ripples that form on the surface of droplets. Because of their size, these ripples—called thermal-capillary waves—cannot be distinguished by the naked eye or even the most advanced experimental techniques.
By using the supercomputer simulations, however, the scientists were able to discover that the first contact made between nearby liquid droplets is actually through these tiny waves, which essentially bridge the gap between droplets until they are combined. The scientists liken the phenomenon to a zipper being done up.
According to the researchers, this discovery could itself have ripples into other fields, including additive manufacturing, where understanding how droplets merge could make 3D printing technologies more accurate. In the weather context, the project could help to better understand the conditions that cause raindrops to form in storm clouds.
“We now have a good understanding of how droplets combine at a molecular level,” said Sreehari Perumanath, Lead research from the University of Edinburgh’s School of Engineering. “These insights, combined with existing knowledge, may enable us to better understand rain drop growth and development in thunderstorms, or improve the quality of printing technologies. The research could also aid in the design of next-generation liquid-cooling systems for new high-powered electronics.”
The research relied on the ARCHER UK National Supercomputing Service, operated by the university’s computing facility, to complete the simulations. The process reportedly required thousands of processors to model the interactions of nearly five million atoms. The study was recently published in the journal Physical Review Letters.
Dr James Sprittles, from the Mathematics Institute at the University of Warwick, added: “The theoretical framework developed for the waves on nanoscale droplets enabled us to understand Edinburgh’s remarkable molecular simulation data. Critically, the new theory allows us to predict the behaviour of larger engineering-scale droplets, which are too big for even ARCHER to capture, and enable new experimental discoveries.”