50.000 times smaller than a Human Hair
I would like to show you a truly beautiful colorized FE-SEM micrograph of sparse network of isolated individual Single Wall Carbon Nanotubes (SWCNT), prepared by CVD using Cobalt nanoparticles as a catalyst and Alcohol as a Carbon Source and grown onto standard Si/SiO2 chips.
They really are beautiful: just as optical fibers have both a practical use for broadband and are really nice to look at, these nanotubes should have huge practical impacts on the way we live, but are pretty in to the bargain. For synthesis I used a mixture of argon and hydrogen as a carrier gas, normal tube furnace with the temperature of substrate close to 900 °C. Chemical Vapor Deposition (CVD) is simple and versatile technique for nanotube synthesis and such networks shows excellent conductivity, transparency and flexibility.
Note that prepared carbon nanotubes have diameter approximately 1-2 nm, a way below the resolution limit of most SEM machines, but the reason, why you actually can see them is because I used special conditions, which allows charging of the nanotubes in the network. I used the excellent Zeiss Ultra 55 microscope, and the artificial purple and yellow colors are added solely for an aesthetic impression, they have no physical meaning.
The hair fragment on the picture is probably mine, since it is very damaged, broken and brittle. It's also slightly thinner than usual hair.