A couple years ago, my lab created a technology that turns a variety of materials superhydrophilic.
Superhydrophilic means it actually attracts water. We actually turned the surface hydrophilic
to such a strong degree that water runs uphill against gravity. That technology can have
many applications on its own. After that, we started to work on the counterpart technology,
making surface to repel water or as we call it, hydrophobic. We have been working on creating
superhydrophobic material using a laser processing technique. What we see here is pretty interesting.
The water falls to wards the surface and is repelled and bounces off the surface. This
is achieved by creating a unique pattern of surface structures at micro and nano scales
with our laser processing technology and those structures are intrinsically part of the material’s surface.
Most of the hydrophobic surfaces available today rely on chemical coatings.
Our surface has many advantages over the coatings out there. First our surface has a much stronger
hydrophobic effect than the coatings and secondly, we don’t have to worry about coatings peeling
off and the surface degrading over time. Many people think of Teflon as a strong hydrophobic
material. However, if you want to get rid of water on a Teflon surface you have to tilt the
surface to about 70 degrees before the water starts to slide off slowly. Our surface requires
an extremely small angle, if at all, for water to slide off. I think there are many possible
applications for this new superhydrophobic surface. For instance, if a surface repels
water, you will also prevent icing on the surface, you will be anti-corrosive and there’s
sanitation applications as well. We wanted to create this superhydrophobic surface that
will not only repel water but also repels water containing a waste materials. We know
in many developing countries in the world, clean water is a scarce resource so if you
create a toilet instead of using a lot of water to flush the toilet, would require little
or no water but still stay clean and dry.