New Process Creates Surfaces That Never Get Wet
Kevin J. Harrigan | January 23, 2015Researchers at the University of Rochester in Rochester, N.Y, have developed a laser etching technique that produces permanent, super-hydrophobic metal materials. (Watch a video of the technology in action.)
Using ultra-short and powerful femtosecond laser pulses, the energy creates micro- and nano-scale patterns in a metal material that rebounds water droplets. Researchers say this technology has the potential to create automotive components that never rust or ice over.
In one quadrillionth of a second, the laser creates a metal surface that is significantly more hydrophobic than one applied with chemical treatments, such as silicon polymers. It is also an upgrade to polytetrafluoroethylene (for example, Teflon), which requires a steep incline before water rolls away. By contrast, the laser-etched pattern repels water at inclines as low as 5°.
The largest benefactor from this process will likely be the transportation industry. Ice accumulation poses risks for automobiles and airplanes alike. Treated metals are more efficient solar absorbers, resulting in a natural material temperature increase that can help guard against ice accumulation. Autos that can repel moisture will be at decreased risk from salt corrosion caused by road deicers and coastal humidity. Researchers also found that etched components exposed to water were cleaner than before.
The research team was led by optics professor Chunlei Guo, who says that limitations exist to the technology. For one thing, the current manufacturing process is slow, processing one square inch per hour, so scaling developments are necessary. The process also isn’t compatible with paint or other surface finishes. Guo and his team hope to expand the technology to semiconductor and dielectric material manufacturing, where upscaling pressures are less significant. Nonetheless, numerous other automotive components of the undercarriage, engine and chassis could benefit from a super-hydrophobic etching process.
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