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We
characterize our plasma-processed samples in several different ways.
We make extensive use of the central
instrument facility (CIF) that is available in the department,
but we have also purchased some instruments of our own either
because
it is a technique that we use routinely or because it provides information
that is unique to our applications. The
pictures to the left and below show the Nicolet Fourier-transform
infrared spectrometer and contact angle goniometer
in our second floor lab. Our FTIR instrument provides a quick means
of characterizing plasma-processed samples in the lab. The contact
angle goniometer is a more unique instrument that we use to characterize
a surface’s affinity for a given liquid. For many applications,
the liquid that we’re interested in is water, 
and
by measuring the contact angle of a water droplet on the sample surface
(viewed
from the side as in the inset), it is possible to get an idea of
the surface’s hydrophilicity or hydrophobicity. Large contact
angles (greaer than 90°) are expected for hydrophobic surfaces,
whereas on hydrophilic surfaces droplets may exhibit low contact angles
(less than 45°) or even be absorbed into the material. Finally,
this lab also houses our profilometer, which allows us to measure step
heights on substrate surfaces for the determination of etching and
deposition rates.