Sharp tip or dull tip?

Rachelle posted on Fri, Jan 11 2013 12:15 PM

rated by 0 users

Hello,

I recently read an article (Langmuir, 28, 16060) in which they analyze sharp tips vs. dull tips for PeakForce QNM. They report that the dull tip gives a more accurate modulus because it decreases the maximum stress applied to the surface. This makes it possible to stay within the linear limits of stress/strain as determined with DMA. This this apply to all samples? Only Bulk? Only thin films?

Also, they report that using the JKR model instead of the DMT model improves the accuracy of the modulus data collected.

Any thoughts?

Thanks,

Rachelle

University of Georgia