Biomedical Engineering Reference
In-Depth Information
FIGURE 1.8
Multiwall carbon nanotubes with a diameter of 30 nm and length of 12
μ
m have been formed
within 2 min
[7]
.
write, as well as read nanoscopic features on a surface. These attributes make DPN a valuable tool for
studying fundamental issues in colloid chemistry, surface science, and nanotechnology. For instance,
diffusion and capillarity on a surface at the nanometer level, organization and crystallization of particles
onto chemical or biomolecular templates, monolayer etching resists for semiconductors and nanometer-
sized tethered polymer structures can be investigated using this technique. In order to create stable
nanostructures, it is beneficial to use molecules that can anchor themselves to the substrate via chemi-
sorption or electrostatic interactions. When alkanethiols are patterned on a gold substrate, a monolayer
is formed in which the thiol head groups form relatively strong bonds to the gold and the alkane chains
extend roughly perpendicular to surface. Creating nanostructures using DPN is a single step process
which does not require the use of resists. Using a conventional AFM, DPN has been reported to achieve
