The Quest for Nanomechanical Measurements with AFM: Are We There Yet?
Dalia Yablon, Ph.D. - SurfaceChar LLC.
Due to the inherently mechanical tip-sample contact, AFM is primed to make long-sought measurements of mechanical properties such as modulus, adhesion, and dynamic moduli on the nanoscale. But are we there yet? Can we say today that AFM can truly perform accurate, quantitative nanomechanical measurements? There has been significant progress since the early days of force volume and phase imaging measurements. Progress will be discussed in two specific categories of nanomechanical measurements: contact resonance and force spectroscopy. Though both techniques have existed for a long time, recent significant improvements in both hardware and software capabilities reveal promising results in the quest for accurate and quantitative measurements. Progress in these capabilities will be discussed with application to polymeric materials in addition to limitations and uncertainties that still need to be addressed.
Improving the Accuracy of AFM-Based Nanomechanical Measurements
Bede Pittenger, Ph.D. - Bruker Nano Surfaces
The morphology and mechanical properties of sub-micron features in materials are of interest due to their influence on macroscopic material performance and function. Atomic Force Microscopy has the high resolution and force control to directly probe the mechanical properties of a wide range of these materials. Over the past two decades, several AFM based methods have evolved to allow this sort of mechanical mapping, each with specific strengths. While qualitative maps have long been available, much progress has been made toward increasing the repeatability and accuracy of the mechanical property maps. Expanded modeling, better calibration, and more optimal probe design have all contributed, resulting in improved ease-of-use and accuracy. This presentation will review this recent progress, providing examples that demonstrate the dynamic range of the measurements, their repeatability, and the speed and resolution with which they were obtained. Examples cover the range from very soft biomaterials and cells, through polymer blends and composites, to metals and ceramics.