Leave It to Beaver: Why a furry wetsuit could keep you warmer and drier.

Beavers and sea otters lack the thick layer of blubber that insulates walruses and whales. And yet these small, semiaquatic mammals can keep warm and even dry while diving, by trapping warm pockets of air in dense layers of fur.

Inspired by these fuzzy swimmers, MIT engineers have now fabricated fur-like, rubbery pelts and used them to identify a mechanism by which air is trapped between individual hairs when the pelts are plunged into liquid.

The researchers are particularly interested in improving wetsuits for surfing, “where the athlete moves frequently between air and water environments,” says Anette (Peko) Hosoi, a professor of mechanical engineering and associate head of the department at MIT.

Biologists had observed that beavers and other semiaquatic mammals trap, or “entrain,” air in their fur. But, as graduate student Alice Nasto notes, “there was no thorough, mechanical understanding of that process. That’s where we come in.”

The team laid out a plan: fabricate fur-like surfaces of various dimensions, plunge the surfaces into liquid at varying speeds, and use video imaging to measure the air trapped in the fur during each dive.

“We have now quantified the design space and can say, ‘If you have this kind of hair density and length and are diving at these speeds, these designs

will trap air, and these will not,’” Hosoi says.

Ah science! Working so hard to do what nature does without thinking. Not much new in this news, I admit, but I like the graphic. Given the temperature outside yesterday I can understand the need for really efficient entrainment.

I found out this weekend that Lorne Fitch from Cows and Fish is accepting our offer of a transportation scholarship and coming to the State of the beaver conference in February! Whoo hoo! The line up looks really grand with folks from Whales, Scotland AND Germany flying out to present their beaver work, as well as American experts like Suzanne Fouty, Mike Callahan, Damion Ciotti and um, me. I also found out that stalwart beaver champions Sharon and Owen Brown of Beavers: Wetlands and Wildlife will be presenting there. Which is wonderful because I always get a little tired of hearing about ‘beavers as a means to an end’ by Friday! The video below is theirs and narrated by Sharon. You should really think about being there. We’re renting a house so we’d invite you for dinner and everything.

I’m not sure what to think about the Whit Gibbons learning curve. He wrote back that he’d look at the website and I sent him all sorts of educational links. His column is obviously syndicated and has appeared in a few other papers. But today’s appearance bears this headline: