Biomedical Engineering Reference
In-Depth Information
prevent a developed discussion of these methods. The
reader is referred to many comprehensive topics on the
general subject of surface analysis (
Andrade, 1985; Briggs
and Seah, 1983; Feldman and Mayer, 1986; Vickerman,
1997
). References on specific surface analysis methods
will be presented in sections on each of the key methods.
Contact angle methods
A drop of liquid sitting on a solid surface represents
a powerful, but simple, method to probe surface proper-
ties. Experience tells us that a drop of water on highly
polished automobile body surfaces will stand up (bead up),
A
B
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C
D
E
F
Fig. 3.1.4-3 What might be measured to define surface structure? (A) Surfaces can be rough, stepped or smooth. (B) Surfaces can
be composed of different chemistries (atomic, supramolecular, macromolecular). (C) Surfaces may be structurally or compositionally
inhomogeneous in the plane of the surface such as phase-separated domains or microcontact printed lanes. (D) Surfaces may be
inhomogeneous with depth into the specimen or simply overlayered with a thin film. (E) Surfaces may be highly crystalline or disordered.
(F) Crystalline surfaces are found with many organizations such as a silicon (100) unreconstructed surface or a silicon (111)(7 7)
reconstructed surface.
