Chunlei Guo, a researcher from the University of Rochester, along with a team of scientists, have created a slab of metal that can push water uphill, defying gravity, by using the capillary effect. It’s the same effect that happens when you put a piece of fabric in a wine glass, for example, and hold it with your hand. The water binds to the material and rises itself, as a combined action of capillarity and evaporation.
Guo and his assistant, Anatoliy Vorobyev, used a laser with the power of the entire grid of North America, but concentrated in a femtosecond (10^-15). “We can even control the direction in which the liquid flows, or whether liquid flows at all,” says Guo.
The metal nanostructures that Guo created change the way liquid molecules of interact with the metal’s molecules, allowing them to become more or less attracted to each other, depending on Guo’s settings. At a certain scale, the metal nanostructures are more prone to sticking to the liquid’s molecules than the liquid’s molecules adhere to each other, causing the liquid to quickly spread out across the metal. Combined with the effects of evaporation as the liquid spreads, this molecular interaction creates the fast wicking effect in Guo’s metals.
In the natural environment, trees do this with their capillary tubes, but Guo’s piece of metal can lift microscopical amounts of water a centimeter per second. This modified metal surface could have great applications in medical devices, since, for example, you won’t have to give a whole test tube for analysis, but rather a scratch would do it.
Chunlei Guo has also invented other materials with the aid of the femtosecond laser: a hydrophobic surface (the microbes are made primarily of water, and can’t stick to it), and a modified light bulb that consumes about 40% less electricity than unmodified light bulbs, reviving this technology and keeping the pleasant light incandescent bulbs give.