The formation of ice on various surfaces has long been a problem, causing problems for roads, airplanes, wind turbines and power lines. However, scientists at Dalian University of Technology have recently developed a fundamentally new solution to this problem. They have created a new structure made of copper nanowires that is capable of passively clearing ice from surfaces with an efficiency approaching 100%.
De-icing systems have been developed and tested for years, but many require chemical coatings or include nanoscale structures that prevent water and ice from bonding. Others use electricity to heat surfaces impregnated with graphene or carbon nanotubes, while still others use magnetic coatings to allow ice to slide off easily.
Specialists at Dalian University of Technology have taken a different approach. They have developed assemblies of copper nanowires that can heat surfaces without requiring an artificial energy source. Instead, such structures harness the energy of sunlight, effectively absorbing and distributing heat throughout the array.
Through a series of experiments, the researchers identified the most efficient copper nanowire designs. It was found that vertically arranged nanowires with a minimum gap between them (2-3 microns) are able to capture more than 95% of the sunlight hitting them. The high thermal conductivity of copper made it possible to effectively spread heat over the entire surface. As a result, a superhydrophobic surface with defrosting efficiency approaching 100% was obtained.
While the technology is promising, the researchers recognize that there are challenges that need to be addressed when scaling up production. Xuehu Ma, corresponding author of the study, said, “More general micro/nanomaterial processing methods need to be developed to improve manufacturing efficiency, material scaling, and surface durability.”
Despite these challenges, the design concept of copper nanowire structures serves as a compass for future research, especially in cold regions where electricity is scarce.