A swatch of MIT's new bio-inspired wetsuit material. (Image courtesy of MIT.)
As part of MIT’s STE@M (Sports Technology and Education at MIT) initiative, students have been tasked with finding new ways to enhance human athletic performance through technology. During a 2015 trip to Taiwan, mechanical engineering professor Anette Hosoi and her students visited a wetsuit manufacturer. That encounter touched off a research project that would culminate in a new, versatile material.
“Surfers, who go in and out of the water, want to be nimble and shed water as quickly as possible when out of the water, but retain the thermal management properties to stay warm when they are submerged,” said Hosio.
Faced with this challenge, Hosoi pushed her students to look for natural substances or materials that could meet a surfer’s needs. Within short order, graduate student Alice Nasto identified semi-aquatic mammals like otters and beavers as the perfect analogue for a wetsuit’s ideal behavior.
For some time, biologists have known that beavers and otters use two types of fur to keep themselves insulated in their fridgid, liquid habitats. Using long, thin “guard” hairs as an impermeable boundary that keeps their shorter, denser undercoat dry, semi-aquatic mammals can trap warm air next to their skin keeping them well insulated from the surrounding chill.
But while biologist understood the basics of how beavers and otters kept themselves warms, the actual mechanics of how this bi-layered hair suit worked remained a mystery. That’s where the MIT team came in.
Using high-speed video cameras, laser cut acrylic sheets and water, Nasto and her colleagues began testing how the spacing between individual hairs affected their hypothetical material’s ability to trap air and retain heat. After numerous trials, Nasto developed a model that could precisely describe how mammal fur traps air.
“Basically, we found that the weight of the water is pushing air in, but the viscosity of the liquid is resisting flow (through the tubes),” Hosoi explains. “The water sticks to these hairs, which prevents water from penetrating all the way to their base.”
Hosoi continued by explaining that their model could be used to create many types of insulating materials tailored for very specific applications. “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. Which is the information you need if you’re going to design a wetsuit.”
Whether or not furry wetsuits will make it to a beach near you is still in question. However, as a surfer myself, I’m actually really interested in trying one of these garments out. While riding waves is always a blast, getting out of the water in the northern Atlantic or the Pacific coast near the Bay Area is always bracing.
And by bracing, I mean miserable.
Any improvement to wetsuit technology that could eliminate surfing’s one major downfall is just fine by me.
For more news at the intersection of surfing and engineering, find out how Australian surfers created a device to pull garbage and debris out of marinas and ports.