Evaluation (Validation and Verification) - Medical Device Design: Innovation from Concept to Market - page 227

Figure 9.16
Typical scanning electron microscope. (Courtesy Staffordshire University)
the reach of most companies (often priced around $10,000) and need specialist training to use.
Most engineering colleges and universities will have one or more in their materials department.
9.3.4.5 Scanning Electron Microscopes (SEM)
These are unaffordable for all but the largest of global companies, even the annual running
costs would make most technical managers' eyes water. They have the ability to measure at
sub-μm levels (magnifications of up to X500,000) and are the mainstay of virtually all surface
evaluation studies ( Figure 9.16 ). However, because of the detail and amount of information
supplied, some studies can suffer from information overload. 1
9.3.4.6 Atomic Force Microscopy (AFM)
This is another very specialized device that only few commercial industries would own,
but many universities specializing in nanotechnology would have one. The device enables
visualization of a surface to the nanometer (1×10 −9 m) scale. They can also be configured to
measure electric potential.
9.3.4.7 Beam Profile Reflectometry (BPR)
Beam profile reflectometry (BPR) uses a low-power, focused laser beam to analyze the
surface and return information about the coating's thickness, refractive index (which is
closely related to density and composition), and even strain or other structural anisotropy.
It can even cope with surfaces that have complex shapes and/or high local curvature. The
technology, which originated in the semiconductor industry, has been adapted for use on
1 Information overload is when too much data is presented such that it actually confuses those that are
nontechnical. Sometimes this is unintentional. Unfortunately it is sometimes intentional in order to suggest
scientific rigor when there is, in fact, none.