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- 26159
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2013年11月21日 Nature
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" p! E- V+ C2 A: J9 K; V# fA water drop strikes the water-averse wing of a Morpho - _/ b6 \' F6 H9 V2 d) i ]6 l- K' H8 Z- y
butterfly. There are many uses for surfaces that can stay dry, self-clean or
& j; L0 L. `* O, x# b! Iresist icing. Liquid drops hitting such surfaces tend to spread out and then 2 W8 o- E: z0 N, [- |! f6 I
retract before finally bouncing. Many applications benefit from minimizing the , ~" O% l0 b K5 ^5 [) I
contact time between drop and surface, which is generally assumed to occur if & Z m! K6 f6 o9 l
the impacting drop deforms symmetrically. Kripa K. Varanasi and colleagues now 9 X* \: G3 F# H( J, n T, w
show that drops bounce off faster from a superhydrophobic surface with a # T& V1 d: z, Z5 ]2 O
morphology that redistributes the liquid mass so that it no longer spreads and
4 f. Q* h2 \: h+ W g& d0 jretracts symmetrically. Theory and experiments confirm that this strategy ; ` ~) y* k0 w9 R7 z
shortens the contact time between a bouncing drop and a surface beyond what was
) \6 D: O/ D( ~ O/ i' Nthought possible. Photo: A. T. Paxson, K. Hounsell, J. W. Bales, J. C. Bird
Q- [2 t8 n9 T- ], b' C; R& K. Varanasi.
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发表于 2013-11-22 18:25
发表于 2013-11-23 19:31
