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2013年11月21日 Nature
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- V. I! T) z' xA water drop strikes the water-averse wing of a Morpho # F9 y. }7 i- d2 @% D
butterfly. There are many uses for surfaces that can stay dry, self-clean or , K: @+ G) W8 H
resist icing. Liquid drops hitting such surfaces tend to spread out and then . e: s- t6 z' J2 a
retract before finally bouncing. Many applications benefit from minimizing the + [% |5 o+ v, e6 T
contact time between drop and surface, which is generally assumed to occur if
8 C& s% F/ W4 J( A5 z6 pthe impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now . g% w- G/ r8 m2 l, M# e% N
show that drops bounce off faster from a superhydrophobic surface with a
% O% ]# c" P# U7 xmorphology that redistributes the liquid mass so that it no longer spreads and 1 F& J/ s% G. \2 N
retracts symmetrically. Theory and experiments confirm that this strategy 6 ~7 U' S$ z% z% j' r0 u
shortens the contact time between a bouncing drop and a surface beyond what was - L$ R( M0 }5 g) H N/ \" a
thought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird
0 o- D( B/ t8 U. @4 K' h2 M t& K. Varanasi.# F+ Y: T ]* V4 L K
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发表于 2013-11-22 18:25
发表于 2013-11-23 19:31
