Contact Resonance Force Microscopy Techniques for Nanomechanical Measurements
Donna C. Hurley
Contact resonance force microscopy (CR-FM) methods such as atomic force acoustic microscopy (AFAM) show great promise as tools for nanoscale materials research. However, accurate and reliable measurements require the simultaneous optimization of a large number of experimental conditions. Among these variables are cantilever spring constant, applied static load, reference material, and resonant mode (mode type and order). In addition, results depend on the models used for data analysis and interpretation (e.g., choice of contact-mechanics model). All of these parameters are linked in numerous ways that are not straighforward to classify. In this chapter, we present a "user's guide" to quantitative measurements of nanomechanical properties with CR-FM methods. The discussion emphasizes the experimental methods and their practical implementation, providing a snapshot of the state of the art in measurements. We discuss the basic physical principles involved, and show how they can be used to make informed choices about experimental parameters and operating conditions. Experimental data and the results of theoretical models are provided as specific examples of the abstract concepts. Ideas for future work are also discussed, including ways to simplify the measurement process or improve measurement accuracy. In this way, we hope to enable readers both to perform measurements and to optimize experimental conditions for their particular needs. By gaining a better understanding of the underlying measurement principles, more researchers will be encouraged to further extend the technique and use it for an ever-wider range of applications.