Adhesion (Pull-off Force) Measurement
The NanoTest™ adhesion module comprises compressive adhesion testing software that enables the probe to be pressed into the sample up to a pre-determined load (or displacement) and then slowly released. The force required to pull the probe free from the sample surface is measured. The module allows such load-unload cycles to be performed many times in the same spot if required.
A
wealth of information in a single test
The adhesion module enables the adhesion (pull-off force) to be measured
together with other nanomechanical properties in a single
indentation test. The mechanical properties include the
hardness, reduced modulus, elastic recovery parameter, micro hardness
dissipation parameter (related to plasticity index by a geometric constant).
Advantages compared to AFM-based adhesion testing
There are several limitations of AFM-based adhesion testing, including minimal choice of unloading rates, elastic contact only, tip radius is not well defined, and there is a statistical distribution of measured adhesion forces
The NanoTest™ adhesion module has the following advantages:-
- Larger radius probes are used – so that the number of contacting atoms on the probe is more constant and the measured statistical variation of adhesion forces is dramatically reduced
- Higher loading forces are used so plasticity can occur and viscoplastic influence on adhesion can also be studied
- Much higher pull-off forces are measurable
