Biomedical Engineering Reference
In-Depth Information
Direction of
ion beam
(A)
Direction of
ion beam
(B)
Direction of
ion beam
(C)
(D)
FIGURE 16.7
Milling scheme for the micro-cantilevers: (A) A 3
μ
m 7
μ
m
trench is first milled, (B) sample is tilted to 45° with respect
to the gallium ion beam and a 3
μ
m 12
μ
m trench is milled,
and (C) a 180° rotation with respect to the specimen normal
is made and a 3
μ
m 12
μ
m trench is milled. (D) The final
product is a cantilever with a triangular cross section.
Due to their microstructure, the mechanical properties of both enamel and bone exhibit depth
dependency when they are indented.
Figure 16.8
shows the typical nanoindentation results obtained from human enamel. Both the
hardness and elastic modulus decrease as the indentation depth increases, and their values begin to
