We've already heard about water-repellant materials that copy the structure of the lotus leaf. Now, however, scientists have created a flexible optical plastic that wards off liquids even better, and it was inspired by something else – the humble Enoki mushroom.
The material was produced by researchers at the University of Pittsburgh, working in the lab of Assoc. Prof. Paul Leu.
It takes the form of a sheet of polyethylene terephthalate (PET), onto the surface of which is deposited a closely-spaced forest of tall, thin nanostructures with rounded blobs at the top. Enoki mushrooms (pictured below) likewise have long, skinny stems topped by larger round caps.
Called nano-enoki PET, the plastic is transparent, and liquids such as water, milk, ketchup, coffee, and olive oil simply roll off its surface. These combined qualities remain even after 5,000 bending cycles, and could make the material ideal for use in items such as solar cells and LEDs, or perhaps even wearable electronics or flexible lighting.
Its superomniphobic (liquid-repelling) quality alone might also make the plastic a good choice for medical devices that are resistant to bacterial colonization and blood-clotting. And what's more, the production process could be scaled up, so it's not just limited to making lab samples.
All of this being said, though, just how does the material work?
"The nano-enoki mushroom shapes trap a barrier of air between the liquid and the surface," Leu tells us. "The liquid ends up only contacting less than five percent of the structure. Thus, the liquid either easily rolls off or flakes off after drying."
A paper on the research was recently published in the Journal of Materials Chemistry A. The paper was co-authored by Sajad Haghanifar, Anthony Galante, David Pekker and Paul Leu, all from Pitt's Swanson School of Engineering, along with Luke M. Tomasovic from the Georgia Institute of Technology.
Source: University of Pittsburgh
