科学美国人60秒:Antifreeze Surface Fights Ice with Ice

Every year, 20 million tons of salt are dumped on roads and highways across the U.S. to eliminate ice. And airlines spray up to 1,000 gallons of antifreeze on any one plane to de-ice it. But now scientists have come up with what might be a more environmentally friendly alternative. 

"We've often heard the expression, 'It's time to fight fire with fire.' Well I think now it's time to fight ice with ice." Jonathan Boreyko studies fluid mechanics at Virginia Tech. 

And what he means by that is: if ice growth is inevitable, why not design certain areas of plane wings or roads or HVAC systems specifically to attract ice…to control the chaos, and keep ice-forming moisture away from the rest of the surface? Use ice itself…as antifreeze?

To test the idea, he and his team used lasers to cut tiny grooves into aluminum surfaces. Those grooves, once filled with water and frozen, turned into tiny stripes of ice, which indeed kept the rest of the surface 80 to 90 percent frost-free, even in incredibly humid cold air. 

"What's happening is the ice striped areas are just so attractive to the moisture, that it kind of tractor beams all the moisture that's going to the surface towards the striped regions preferentially, such that the intermediate areas, if you design it right, just stay completely dry." 

The results—and some cool time-lapse videos—are in the journal ACS Applied Materials & Interfaces. [S. Farzad Ahmadi et al., Passive Antifrosting Surfaces Using Microscopic Ice Patterns]

Boreyko and his team have already patented the tech. If it proves viable after more R&D, it might make our wintertime fight against frost a lot more environmentally friendly. 

—Christopher Intagliata