This is Scientific American 62nd Science. I'm Cynthia Graber.

Whale seals and walruses stay warm in chilly water because they have a thick layer of blubber.

We humans rely on something like blubber, neoprene rubber

wetsuits to spend time in cold water, but the thick versions for really icy water are

heavy and ungainly. So rather than taking after big marine mammals, what if we could learn from the

littler ones like beavers and otters?

These animals are quite small and they can't carry around a thick layer of blubber, so instead they have fur that has evolved to trap air.

And this air provides a layer of insulation for them in water.

Alice Nastow is a graduate student in mechanical engineering at MIT.

Scientists have known about this air-trapping insulation mechanism for a long time,

but they had not teased out the details of how it works.

So Nasto and her colleagues took on the

challenge. We are creating these furry samples from these rubbery materials

by a laser cutting mold and casting these hairy surfaces and through our approach we can precisely

control the spacing of the hairs the length of the hairs.

The researchers then created a system to gather data when the

pelts entered and moved through a liquid, in this case not water but silicone

oil which makes it easier to see air bubbles. The key is to keep the pelts air

layer intact.

So when they're crossing the air water interface,

initially their hairy texture is full of air,

and then you go into water,

...