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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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2013年11月21日 Nature1 K9 g& O3 d3 `, k2 R* u5 j! t- s
, E( l" `: Q% k8 \4 Q3 |/ O2 F& BA water drop strikes the water-averse wing of a Morpho
+ n7 G* R" d! e. _6 d" sbutterfly. There are many uses for surfaces that can stay dry, self-clean or 9 H2 Q; h' l4 ^% _0 s
resist icing. Liquid drops hitting such surfaces tend to spread out and then
# b2 `4 g1 |" n% D c3 }& I4 ^retract before finally bouncing. Many applications benefit from minimizing the 9 b1 W- h0 ^) c# W. U5 x7 T
contact time between drop and surface, which is generally assumed to occur if 5 k2 W# ]" v1 b5 ]7 E) d
the impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now
* @- c8 h3 Q! J0 c1 I0 E9 Dshow that drops bounce off faster from a superhydrophobic surface with a , B" n* O8 g M+ u$ E
morphology that redistributes the liquid mass so that it no longer spreads and . _3 k# ]8 A+ Y3 Z' Y. N+ ^9 C
retracts symmetrically. Theory and experiments confirm that this strategy
9 i; w. F- O5 Cshortens the contact time between a bouncing drop and a surface beyond what was
0 M2 A. F, I' H9 G j5 v- Rthought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird
( G8 P! R7 \3 H$ F$ o; ]& K. Varanasi.
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发表于 2013-11-22 18:25
发表于 2013-11-23 19:31
