Biomedical Engineering Reference
In-Depth Information
FIGURE 18.4
Interferometer recorded surface topography of blaster surface with (A) a 1 1
μ
m Gaussian filter and
(B) with a 1 1
μ
m Gaussian filter low pass; and a turned surface with (C) a 1 1
μ
m Gaussian filter and
(D) a 1 1
μ
m Gaussian filter low pass
[32]
.
nanoparticles
[36]
. TEM's electron imaging and diffraction options allow property-structure relation-
ships of nanostructures to be understood. It has the resolution to differentiate between nanotubes with
subtle nanoscale structural patterns. Interlayer distances of about 0.34 nm have been measured and
imaged clearly, consistent with the (002) plane lattice parameter of graphited carbon
[37]
.
TEM is well renowned for its high resolution imaging capabilities. However, in recent years TEM
has also gained acceptance as a viable means of measuring the elastic and mechanical properties of
nanostructures
[38]
. Wang et al.
[35]
demonstrated a technique to measure the mechanical strength of
single CNTs using
in situ
TEM. This was done by using an externally applied voltage to induce a charge
in the nanotube
[35]
. The electrostatic force resulted in a deflection of the nanotubes (
Figure 18.5
).
Cyclical loading of the nanotube was achieved by subjecting the tube to positive and negative
voltages. This approach was used to apply a load to an individual nanotube, thus allowing a direct
measurement of its elastic limit
[35]
. Wang et al.
[35]
also employed their
in situ
TEM setup to
