ENGINEERING AND SCIENCE
RESEARCH LABS AND EQUIPMENT
Associate Professor, Mechanical Engineering Department
Combining a depth sensing indentation (nanoindentation) and atomic force microscope (AFM) permit the observation and characterization of various materials, particularly for thin films and localized, small-scale structures ranging from µm to nm. Our integrated nanoindentation system (TriboIndenter, Hysitron, Inc., Minneapolis, MN) consists of a nanoindenter and AFM along with other accessories such as a lateral force option, a dynamic load capability, a feedback control, an automatic translation stage for specimen, a heating/cooling stage, and an optical microscope (Fig. 1).
Figure 1. (a) Integrated nanoindenter/AFM system (b) Schematic of typical loading/unloading curve (c ) in-situ AFM image of indented mark.
This system measures the indentation response during the sequence of loading and unloading when the sharp tip interacts with the surface of the material (i.e., indentation load vs. displacement). It has a capability to characterize both elastic and plastic properties including: i) mechanical performance (hardness, elastic modulus, creep, stress relaxation) and contact problems (wear, coefficient of friction); ii) time-dependent deformation (viscoelasticity) of polymers via dynamic testing; iii) in-situ mechanical behavior at temperatures ranging from -10˚C to 200˚C; iv) thin film properties, thickness measurement, and film adhesion.