When spraying paint or coatings onto a surface, or fertilizers or pesticides onto crops, the size of the droplets makes a big difference. Bigger drops will drift less in the wind, allowing them to strike their intended targets more accurately, but smaller droplets are more likely to stick when they land instead of bouncing off.
When spraying paint or coatings onto a surface, or fertilizers or pesticides onto crops, the size of the droplets makes a big difference. Bigger drops will drift less in the wind, allowing them to strike their intended targets more accurately, but smaller droplets are more likely to stick when they land instead of bouncing off.
Now, a team of MIT researchers has found a way to balance those properties and get the best of both — sprays that don’t drift too far but provide tiny droplets to stick to the surface. The team accomplished this in a surprisingly simple way, by placing a fine mesh in between the spray and the intended target to break up droplets into ones that are only one-thousandth as big.
The findings are reported today in the journal Physical Review Fluids, in a paper by MIT associate professor of mechanical engineering Kripa Varanasi, former postdoc Dan Soto, graduate student Henri-Louis Girard, and three others at MIT and at CNRS in Paris.
Read more at Massachusetts Institute of Technology
Photo: Photos illustrate how the tiny droplets produced by a mesh barrier prevent plants from being pummeled by the larger droplets from either rainfall or the spraying of pesticides, herbicides and fertilizers. The smaller droplets in the image at right have little effect on the plant, while the droplets at left batter its leaves heavily. Courtesy of the Varanasi Research Group
