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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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2013年11月21日 Nature& ?% o; l) n) T* R% J7 p0 i) a+ T
C9 r* o0 `; S6 u7 j& kA water drop strikes the water-averse wing of a Morpho % Q% k7 j& T" m+ C5 O* c5 |# w
butterfly. There are many uses for surfaces that can stay dry, self-clean or v/ G! s/ _' L" q
resist icing. Liquid drops hitting such surfaces tend to spread out and then ( T/ L9 _! p% z o, b9 [" S3 Q
retract before finally bouncing. Many applications benefit from minimizing the ) p$ y. z% d: ~5 S2 H* b; p
contact time between drop and surface, which is generally assumed to occur if * b% C9 {, u. x: w5 T
the impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now + O2 S3 X1 F$ L6 z
show that drops bounce off faster from a superhydrophobic surface with a
& w. k( |1 o5 d w: Z' G- Qmorphology that redistributes the liquid mass so that it no longer spreads and
) W" U$ q9 Y1 i+ \+ s xretracts symmetrically. Theory and experiments confirm that this strategy
5 F8 h5 G7 u7 pshortens the contact time between a bouncing drop and a surface beyond what was : Q' I& ~: H G1 Z$ Y
thought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird % K; ~, j) C8 B) H
& K. Varanasi.
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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
