Why penguins don’t freeze? This is possibly a question that everyone of us have asked at least once. If not, this is the time you not just ask but also get an answer unlike many of us who had to wait a long time to get to the base of this mystery.
Penguins are known to love low temperatures. They usually swim in waters that have a temperature of 0 degrees Celsius or 32 degrees Fahrenheit. They perform just perfectly fine when the temperatures drop as low as -40 degrees Celsius or -40 degrees Fahrenheit. They never freeze. They never get coated with snow. So, what helps them? What is the secret of their amazing capabilities of surviving sub-zero temperatures where humans will just succumb to death without proper clothes?
This was actually a mystery for long and the most commonly accepted notion was that they are blessed with very thick feathers that don’t allow cold water or cold air reach their skin. It was also believed that while swimming, they swim fast enough to prevent ice layers build up on their feathers. No matter how ridiculous those notions sounded, they prevailed until now when Beihang University researchers decided to do some digging.
So, why penguins don’t freeze?
In order to answer this question, Beijing’s Beihang University researchers teamed up and focused on Spheniscus humboldti or Humboldt Penguins. These penguins are usually found in coasts of Chile and Peru but the researchers turned to samples that live in Beijing Pacific Underwater World.
The question is, why on earth did these researchers decided to unlock the mystery? That’s because until now, no one was able to artificially recreate superhydrophobic coating or the ultra-water-resistant coating that everyone believed the penguins had in form of their very thick feathers.
So, the researchers knew that the answer to this amazing mystery was not simple and requires some serious digging. They conducted their study which was later published in Journal of Physical Chemistry. The study can be found online here.
For the purpose of their study, the researches collected feather samples from the penguins in Beijing Pacific Underwater World. They actually had to cut off some feathers. Once the feathers were collected, they brought them back to their laboratory and put them under electron microscope. They found something interesting. They found the answer to the mystery that riddled mankind for long.
When put under scrutiny of electron microscope, the feathers revealed some special characteristics that work in conjunction with each other to prevent the penguins from freezing. The researchers found that the grooved feathers are arranged in layers and between the layers, air remains trapped. To prevent the air from escaping from the grooved layers, there are microscopic barbs which hold these feather layers together.
On top of that, the feathers have two characteristics – antiadhesion and hydrophobicity. These characteristics prevent water from entering the feathers and stick to them! Shuying Wang – a material scientist in the team of researchers was quoted saying:
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.
Recreation of hydrophobic material
Now that the researches unlocked the mystery and answered the question – why penguins don’t freeze, it was time for them to create a material that would replicate the properties of penguin feathers!
The researchers used a high pressure electrospinning device to weave together thin polyimide fibers. The resulting material wasn’t really an exact replica of what penguins naturally have but, the end result was far better that any hydrophobic material previously made.
The scientists decided to put the artificial feathers to test and for hours they sprayed these feathers with cold water having a temperature of -5 degrees Celsius or 23 degrees Fahrenheit. Interestingly, water did not stick to the feathers and no ice crystals were formed either.
This was an amazing breakthrough and perhaps, this secret will someday help to produce super hydrophobic electric cable insulations or superhydrophic swimsuits for chilling waters. The applications of this new knowledge can help us combat cold weathers in a far more efficient manner than what we have been doing since the dawn of humanity.
So, now that you know why penguins don’t freeze, can you think of possible ways this knowledge can be put to work?