Atomic Force Microscopy
This powerful tool is used to measure properties of a sample surface. Properties include roughness, height, depth and force. Yields topographic images and allows structure and detail to be seen with high resolution and without the need for rigorous sample preparation.
Theory of Operation
The system uses a sharp tip on the
end of a long cantilever. In Contact Mode, tip-to-sample
spacing is held fixed by maintaining a constant very low force
on the cantilever, pushing the tip against the sample. The
force is in the range of inter-atomic forces (about 10E-9N), thus the name “atomic force” microscopy. The force is
low enough to usually cause no damage to the surface being
measured. With tapping mode AFM, contact of the cantilever
probes with the sample is minimised, thereby damage to the
sample while imaging in minimised.
The vertical motion of the tip as it
slides over the sample surface is detected by a beam deflection
system that uses a laser shining and reflecting off the back of
the cantilever and onto a photodiode.
- Used for the microstructural
characterisation of biomaterials
by analyzing the topography, component distribution and
architecture of composites made of collagen and elastin-like
polymers.
- Used to
quantitatively
study the surface of micro- and
nano-structured polymers and metals that had been patterned
using various laser techniques.
- Thin film thickness measurements
can pose a significant challenge and it is a parameter that
can have significant importance in the microelectronic and
biotechnological arenas. AFM is used to predict the
thickness of submicron scale films.
CMI AFM systems:
Dimension 3100 AFM