See if you can find the 8 differences in each set of images.
The proposal flowers of Mr. Copper to Ms. Nutmeg Myristica fragrans
Microscale clusters of copper-myristic acid formed on a copper foil. Imaged with a secondary electron detector using Zeiss Ultra FE SEM.
Philseok Kim, Harvard University, Cambridge, Mass., USA
June 2015 answer key
Pearl on grass
The rich purple “pearl” is a sessile water droplet (D ∼ 500 µm) on a superhydrophobic surface, which was created by first growing a rough copper oxide nanostructure on a copper substrate in a heated alkaline solution, and then this nanostructure was functionalized with a fluorocarbon coating. The clouds in the calm blue “sky” are microdroplets bouncing on the same superhydrophobic surface, but out of the focal plane of the high-speed camera used to capture the image. The soft green “grass” is a dense carpet of carbon nanotubes (D ∼ 10 nm) imaged with field-emission scanning electron microscopy, which was digitally superimposed onto the image of the droplet.
Daniel J. Preston, Massachusetts Institute of Technology, Cambridge, Mass., USA
The answers will be in the October 2015 issue.