Nanoindenter

• Subject Area: Materials Engineering
• Term: Funded in 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544085364

Nanoindentation (instrumented penetration test) is a material testing method for determining the hardness of materials on small length scales (20 nm - 20 µm). The main area of application is determining the hardness of thin layers in materials science. Nanoindentation has now found an application in the biomechanics for the characterization of hardness and stiffness of biological materials. Nanoindentation is derived from classic hardness testing, but takes place on a much smaller scale. A hard tip with a known geometry is pressed into the surface to be tested. During nanoindentation, the applied indentation force and the indentation distance of the tip are measured simultaneously during the experiment. Using the known geometry of the test tip and the measurement data for indentation force and indentation distance, the contact area and subsequently the hardness can be calculated. For their current and planned projects, the working groups involved in this application require a well-equipped nanoindenter that is capable of precise quasi-static and continuous stiffness measurements (CSM), dynamic nanomechanical tests, in-situ topography and property mapping, nano-scratch tests and measurements on wet samples, which is of crucial importance for biological samples. The samples to be examined in the planned projects are complex in terms of their material composition, as well as their geometry and their mechanical behavior and are typically a few hundred micrometers in size. The precise determination of the material properties of such samples would therefore first require high-resolution topography and property mapping. Furthermore, in most cases, biological samples are viscoelastic, so dynamic CSM testing is required to characterize storage modulus, loss modulus, complex modulus, and loss factor. The nano-scratch module is also required for characterization of the tribological properties. The applicants have shown that currently only the two devices considered here have such a combination of modules that can fully meet the requirements.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Nanoindenter
• Instrumentation Group: 2930 Härteprüfmaschinen, Reibungs- und Verschleiß-Prüfmaschinen
• Applicant Institution: Christian-Albrechts-Universität zu Kiel
• Leader: Professor Dr. Stanislav N. Gorb