“We are particularly interested in wetsuits for surfing, where the athlete moves frequently between air and water environments. We can control the length, spacing, and arrangement of hairs, which allows us to design textures to match certain dive speeds and maximize the wetsuit's dry region,” said Anette (Peko) Hosoi, a professor of mechanical engineering and associate head of the department at MIT.
In order to develop the perfect fabric for the intended wetsuits, the team fabricated fur-like surfaces of various dimensions, plunged them into liquid at different velocities and measured the air that got trapped in the fur in each dive using video imaging.
Nasto created various molds using the laser-cutting technique on small acrylic blocks to make hairy surfaces and used a software program to change the size and spacing of individual hairs. These molds were then filled with a soft casting rubber called PDMS (polydimethylsiloxane) and hairy surfaces were then pulled out of them. Various experiments were then carried out on these hairy surfaces.
The air trapping effect of the hairy surfaces were represented in mathematical terms and applied to experimental data. The predictions of the scientists' matched the data.
“Basically we found that the weight of the water is pushing air in, but the viscosity of the liquid is resisting flow. The water sticks to these hairs, which prevents water from penetrating all the way to their base,” explained Hosoi.
The research published in the journal Physical Review Fluids has been authored by Hosoi, lead author and graduate student Alice Nasto, postdoc José Alvarado, and applied mathematics instructor Pierre-Thomas Brun, all from MIT, as well as former visiting researcher Marianne Regli, and Christophe Clanet, both of École Polytechnique, in France. It was partly funded by the National Science Foundation. (KD)
Fibre2Fashion News Desk – India