Researchers Look to Lotus Leaves for Water-Repellent Polymer
May 30, 2006
Research taking place at General Electric could allow everything from new, easy-to-clean building materials to cheap diagnostic devices with plastic microfluidic channels; from dusty DVDs to a ketchup bottle whose contents flow freely; perhaps even self-cleaning cars.
While GE is being somewhat secretive about the process, one of the company's materials scientists, Tao Deng, says it uses a "chemical treatment of the surface."
In designing the material, the GE researchers took inspiration from the leaves of the lotus plant, the surface cells of which are five to ten micrometers wide and topped by tiny wax crystals that are tens of nanometers wide. On a lotus leaf, water beads look like almost perfect spheres.
GE mimicked this pattern on Lexan by "roughening" its surface in a similar way. "What we are trying to do is to make a GE polymer, a hydrophilic material, shed water the way a lotus leaf does," according to GE's Global Research blog.
[The] answer lies in the roughened wax nano-structure on the leaves. As water rolls off the surface, it picks up dirt and keeps the surface clean this effect is called "self-cleaning". With the magic of turning hydrophilic polymers into superhydrophobic surfaces, we are expanding the application of our polymers into many new areas that would benefit from self cleaning properties.
While self-cleaning cars are the first thing that come to mind, the discovery could allow everything from new, easy-to-clean building materials to cheap diagnostic devices with plastic microfluidic channels, from dusty DVDs to a ketchup bottle whose contents flow freely.
GE estimates it will take at least five years to commercialize the technology, once all manufacturing issues are resolved.
Image credit: Perry/BrightGardens.com