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- 积分
- 17983
- 威望
- 17983
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- 26159
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2013年11月21日 Nature3 ^; _) Y/ I# f& f# m
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A water drop strikes the water-averse wing of a Morpho : y# j, w$ b r' J5 y/ ~& z
butterfly. There are many uses for surfaces that can stay dry, self-clean or 0 X1 T' `4 [0 W* ]
resist icing. Liquid drops hitting such surfaces tend to spread out and then
, r9 o, \; l5 o0 q; ^- \retract before finally bouncing. Many applications benefit from minimizing the / E; j9 x: g# A/ p8 o) ^7 f! e
contact time between drop and surface, which is generally assumed to occur if 1 L8 C) }: F0 ?8 q
the impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now 9 o, a, T' v, B
show that drops bounce off faster from a superhydrophobic surface with a 8 W% e; K* ^3 _ L4 J
morphology that redistributes the liquid mass so that it no longer spreads and
% S/ d; P. G. v$ jretracts symmetrically. Theory and experiments confirm that this strategy * K. L, Y9 K# m& g0 u7 O3 }. |1 _* p
shortens the contact time between a bouncing drop and a surface beyond what was 4 U8 W5 b" _7 d& v' D! q- }1 w
thought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird
1 w/ V# K% M2 ?( f2 a/ T; u( b3 s& K. Varanasi.7 l1 ?1 R0 X, _% d2 `1 M
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总评分: 威望 + 20
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发表于 2013-11-22 18:25
发表于 2013-11-23 19:31
