When designing micro- or nanoelectromechanical systems, (MEMS and NEMS), it is important to consider whether structural elements will withstand loads experienced during operation. Fracture behavior at length scales present in MEMS and NEMS is much di erent than at macro- and mesoscopic scales. Due to a smaller probability of crystal defects and a high surface to volume ratio, fracture is controlled by surface characteristics rather than volumetric ones. Prior measurements using doubly clamped Si beams loaded with an atomic force microscope (AFM) showed that fracture of Si nanobeams is highly a ected by surface roughness  and oxidation . In experiments of this type, calibration of the system, particularly the AFM cantilever sti ness, is critical to the accuracy of both the force and displacement results. A new set of experiments are underway in which the tests are performed by adapting a direct, traceable method for calibrating the AFM cantilever sti ness . The improved calibration should not only improve the accuracy of the strength results but will allow linear sti ness measurements of the sample to be used to back out sample thickness, a key parameter in interpretation of the data.
Proceedings Title: SEM XII Internalional Congress & Exposition on Experimental and Applied Mechanics
Conference Dates: June 11-14, 2012
Conference Location: Costa Mesa, CA
Conference Title: Measurement Challenges for New Structures and Materials
Pub Type: Conferences
AFM, calibration, cantilever, nanoindenter