Biomedical Engineering Reference
In-Depth Information
Figure 4.1
Schematic representation of the building up of nanostructures.
Both approaches play a very important role in modern industry
and most likely in nanotechnology as well [59]. There are advantages
and disadvantages in both approaches. High energy ball milling is
a typical top-down method in making nanoparticles. The biggest
problem with top-down approach is the imperfection of surface
structure and signiicant crystallographic damage to the processed
patterns. Regardless of the defects produced by top-down approach,
they will continue to play an important role in the synthesis of
nanostructures.
Although the bottom-up approach is frequently referred in
nanotechnology, it is not a new concept. Currently, it plays an
important role in the fabrication and processing of nanostructures.
It is important to note, that the produced materials can have
signiicantly different properties, depending on the route chosen
to fabricate them. Apart from direct atom manipulation, there are
various widely known methods for producing nanomaterials:
mechanical, wet chemical, form-in-place, and gas-phase synthesis
[55, 56].
