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- 积分
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2013年11月21日 Nature
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; l: [ e. k( k4 k$ q8 MA water drop strikes the water-averse wing of a Morpho 8 T3 n/ ^( s4 {& W* P8 \" \
butterfly. There are many uses for surfaces that can stay dry, self-clean or % a. {* @5 U. J+ k
resist icing. Liquid drops hitting such surfaces tend to spread out and then
5 T ^! O f9 r4 ^retract before finally bouncing. Many applications benefit from minimizing the , G U& V$ x* X* _( b8 y# d* M2 @4 R
contact time between drop and surface, which is generally assumed to occur if 4 o. }5 S5 Y( U9 m( g/ s6 M
the impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now ; p( _, J# ?+ r8 W) y: J/ E3 F: H2 M
show that drops bounce off faster from a superhydrophobic surface with a
* T6 n7 e E: r W4 l/ i% Nmorphology that redistributes the liquid mass so that it no longer spreads and + q, g4 V$ G3 E z9 a# S8 f& h
retracts symmetrically. Theory and experiments confirm that this strategy # ^: Z9 z `6 B; {
shortens the contact time between a bouncing drop and a surface beyond what was
" V# R* C7 c. j9 S" l7 Z; Lthought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird
8 B- E7 N- W- ?; C0 Z$ X& K. Varanasi.
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发表于 2013-11-22 18:25
发表于 2013-11-23 19:31
