/These galleries exhibit images of carbon nanotube structures grown by chemical vapor deposition on silicon substrates. The nanotubes self-assemble during growth to form intricate structures; each structure consists of millions to billions of parallel nanotubes, as the density of nanotubes growing from a substrate is about 20 billion per square centimeter. Electron and optical imaging techniques, combined with digital image stitching and color enhancement, are used to create the visual representations shown below.

/Architectures formed by self-organization of carbon nanotubes as they grow upward from the silicon substrate from the catalyst layer. If the catalyst is uniformly distributed, nanotubes grow everywhere on the substrate and how the nanotubes organize is defined by how they push and pull eachother to produce the architectures shown. If the catalyst is only put in certain areas (patterned), then nanotubes grow only from the areas with catalyst. Many of these resemble everyday objects and macroscopic landscapes, but are formed by self-assembly interactions. The images were taken using a scanning electron microscope.
/Architectures formed in the same way as described at left, plus the nanotubes were externally pushed by a mechanical pressure during growth. For example, the Barn shape shown above formed as the nanotubes were confined to stay within a trapezoidal mold during growth.
Seed of Life
/Digitally-colorized images of self-organized and patterned nanotube architectures.
/Each image here was digitally stitched from several frames, so the extent of the image far exceeds the normal field of view of the scanning electron microscope. Stitching was performed in collaboration with Michael Cohen at Microsoft Research and Felice Frankel at MIT. Felice presented the "Seed of Life" image in her column in American Scientist in 2006.
/Optical photographs of carbon nanotube structures on reflective silicon substrates, taken using digital cameras by Rick Slocum and Ryan Wartena.
c.2007 - ajohnh@umich.edu