作者nfsong (图书馆我来了)
看板PCSH91_305
标题使用雷射让水克服重力逆流
时间Fri Mar 19 22:12:38 2010
http://gizmodo.com/5496727/making-water-run-uphill-with-lasers?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+gizmodo%2Ffull+%28Gizmodo%29&utm_content=Google+Reader
Researchers at the University of Rochester have discovered how to make liquid
overcome gravity and flow upward along a silicon surface. The essential
ingredient, as always: lasers.
The scientists achieved the curious movement by using short laser blasts to
carve imperceptible patterns into the silicon sheet. That alone prompts the
water molecules to climb upward, without any additional aid:
Unlike a straw, though, there is no outside pressure pushing the liquid
up; it rises on its own accord. By creating nanometer-scale structures in
silicon, Guo greatly increases the attraction that water molecules feel
toward it. The attraction, or hydrophile, of the silicon becomes so great, in
fact, that it overcomes the strong bond that water molecules feel for other
water molecules.
Thus, instead of sticking to each other, the water molecules climb over
one another for a chance to be next to the silicon. (This might seem like
getting energy for free, but even though the water rises, thus gaining
potential energy, the chemical bonds holding the water to the silicon require
a lower energy than the ones holding the water molecules to other water
molecules.) The water rushes up the surface at speeds of 3.5 cm per second.
A fun party trick, but are there practical applications? Actually, yes! This
could be the first step towards new heat regulation strategies for computers.
Instead of fans, we may see liquid cooling systems thanks to silicon that can
pump its own coolant. That method would be more energy efficient, cost
effective, and most importantly a heckuva lot more lasery.
As has been pointed out in the comments, the image above is an optical
illusion and here for illustrative purposes only. [University of Rochester
via CrunchGear]
※ 编辑: nfsong 来自: 59.117.208.57 (03/19 22:19)