Penguins swim in waters that are often below 32 degrees F and live in areas where the temperature drops to -40 degrees F (-40 C), yet you never see them frozen solid, iced-over or even snow covered. How do they do it? Their secret has finally been discovered and it may help humans develop ice-resistant materials.
It has long been assumed that the thick layer of feathers penguins have keeps freezing water from reaching their skin and moving fast in the water kept a layer of from building up on them. However, that level of superhydrophobic coating (ultra-water-resistance) has been impossible to duplicate. Researchers from Beihang University in Beijing decided to unlock (or unfreeze) the secret by studying Humboldt penguins (Spheniscus humboldti).
According to their study in Journal of Physical Chemistry, the researchers collected body feathers from Humboldt penguins at Beijing Pacific Underwater World (Humboldt’s live off the coasts of Peru and Chile). The feathers were cut up and magnified using an electron microscope.
What they found was a combination of characteristics working together to keep the penguins ice-free, said material scientist Shuying Wang.
We found that their air-infused microscale and nanoscale hierarchical rough structures endow the body feathers of penguins Spheniscus humboldti with hydrophobicity and antiadhesion characteristics, even for supercooled water microdroplets.
In simple terms, air trapped between the layers of rough, grooved feathers prevents water from adhering to them, while microscopic barbs hold the layers together. Once they discovered the secret, the researchers attempted to recreate the penguin feathers using thin polyimide fibers woven with a high pressure electrospinning device. While not an exact copy, the artificial feathers were sprayed for hours with water as cold as 23 degrees F (-5 C) without any water sticking to them or ice crystals forming.
While this sounds like the perfect swimsuit material for extreme swimmers like Diana Nyad, it’s more likely going to find better use as insulation for electrical cables.
Let’s hope Mr. Freeze and the Penguin don’t get their hands on the technology first.