Contact resonance force microscopy for nanomechanical characterization: Accuracy and sensitivity

Contact Resonance Force Microscopy (CRFM), based on dynamic force microscopy, is a new promising technique for quantitative nanoscale mechanical characterization of various materials. In this work, we systematically investigated the measurement accuracy and sensitivity of CRFM both experimentally and numerically. For the accuracy study, we first evaluated the validity of the Euler-Bernoulli beam model used in CRFM and found that it is accurate enough for practical testing. Then, the influence of the tip location was also analyzed and results show that it can significantly affect the obtained indentation modulus. The measurement accuracy of CRFM was then compared with that of nanoindentation and it shows that CRFM has less relative testing errors than nanoindentation for modulus mapping but a larger data scattering for single-point measurements. As to the sensitivity study, we first conducted the cantilever-stiffness dependent sensitivity analysis using both numerical and experimental approaches, and suggested that a stiffer cantilever (say 30-50 N/m) is required for characterization of hard materials (say modulus larger than 30 GPa). Then, the sensitivity of different flexural modes of a specific cantilever was tested and it is found that higher flexural modes could provide higher sensitivity especially, when the normalized contact stiffness is large. Finally, the effect of laser spot location on the detecting sensitivity was tested and the optimal location is suggested. This work could provide very helpful guidance to nanoscale mechanical characterization using CRFM. (C) 2013 AIP Publishing LLC.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000323177100066&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EI8ARTICLE6null11