Accurate Tools for Measuring Nanoscale Mechanical Properties for Diverse Materials
Understanding nanoscale mechanical properties is of fundamental importance for evaluating the behavior and performance of a wide variety of industrially, biologically and structurally important materials. An Atomic Force Microscope (AFM) tip interacting with a sample experiences forces originating from many different sources – elasticity, viscosity, adhesion, van der Waals – to name a few. Hence, it has become increasingly clear that reliable and accurate materials properties measurements require looking at your sample in more than one way. Single techniques are simply insufficient for accurately and rigorously revealing sample properties and can often yield misleading and even inaccurate results and conclusions.
The NanomechPro™ toolkit (Figure 1) for Asylum’s Cypher™ and MFP-3D™ AFMs provides a suite of tools to meet the requirements of the nanomechanics researcher and is both impressively powerful and rapidly expanding. The various tools are complementary – each technique probes and records different responses of your samples – and often can be used imultaneously (e.g. Figures 2a – d). Additionally, with the Cypher AFM, many of these new techniques can be combined with small, fast, low noise cantilevers, enabling measurements at noise levels and speeds previously impossible.
Combined Loss Tangent and AM-FM Imaging
Amplitude-modulated (AM) atomic force microscopy, also known as tapping mode or AC mode, is a proven, reliable and gentle imaging method with widespread applications. Previously, the contrast in tapping mode has been difficult to quantify. However, in this work we introduce two new techniques that allow unambiguous interpretation of material properties in tapping mode: AM-FM and Loss Tangent. Because these measurements are made simultaneously, there is a built-in check for self-consistency in the measurements. The new AM-FM imaging technique combines the features and benefits of normal tapping mode with the quantitative, high sensitivity of Frequency Modulation (FM) mode. Both Loss Tangent and AM-FM imaging can be performed simultaneously at high data acquisition rates. These techniques are exclusively available from Asylum Research, US patents 8,024,963, 7,937,991, 7,603,891, 7,921,466 and 7,958,563 with others pending.