Using nanometer etching to change surface adhesion properties

What makes a surface attract or repel water that comes in contact with it is usually determined by the chemical coating on the surface. Teflon is an example of a chemical coating to which water adheres only slightly. Those waxes that are put on wood and metal surfaces that cause water to bead up and flow off rather than adhere to the surface are other examples of hydrophobic techniques.

But scientists at the University of Rochester have developed a technique of using etching patterns on a micro- or nanometer scale that can produce either super-hydrophobic or super-hydrophilic surfaces. The effects shown in the video are quite dramatic.

(Via Mark Frauenfelder.)


  1. moarscienceplz says

    Interesting. I’m guessing that pipes made out of this material would have much less flow resistance, as well as high corrosion resistance.

  2. John Morales says

    My first thought is that such fine etching seems vulnerable to being abraded or coated with gunk, in the real world.

  3. Holms says

    It seems very strange to think that any nanometer scale structure coulf be considered wear resisitant. Surely any detail that fine is going to be highly vulnerable if on an exposed surface, even with a durable material?

  4. Rob Grigjanis says

    John Morales & Holms: I think a large part of the wear resistance is simply that water bounces off it, carrying dust particles with it. So it’s self-cleaning;

    As the water bounces off the super-hydrophobic surfaces, it also collects dust particles and takes them along for the ride. To test this self-cleaning property, Guo and his team took ordinary dust from a vacuum cleaner and dumped it onto the treated surface. Roughly half of the dust particles were removed with just three drops of water. It took only a dozen drops to leave the surface spotless. Better yet, it remains completely dry.

  5. Crimson Clupeidae says

    Interesting. I wonder if the average molecular size of the material that is being etched affects how/if it works?

    I want my protective glasses and motorcycle helmet visor to have this!

Leave a Reply

Your email address will not be published. Required fields are marked *