Regensburg 2013 – scientific programme

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BP: Fachverband Biologische Physik

BP 26: Posters: Biomaterials and Biopolymers (joint with CPP)

BP 26.11: Poster

Wednesday, March 13, 2013, 17:30–19:30, Poster C

Minimization of Errors in the Determination of Elastic Moduli from Indentation Experiments — Michael Glaubitz, Mihaela Delcea, and •Stephan Block — ZIK HIKE, Fleischmannstr. 42 - 44, D-17475 Greifswald, Germany

Atomic force microscopes (AFMs) equipped with colloidal probe (CP) cantilevers allow to determine elastic moduli E with a lateral resolution below 1 µm by indentation experiments. Such experiments were used intensively in the past to study the elastic properties of surface coatings or changes in cell mechanics related to diseases like cancer or cardiomyopathies. Here, we present the first analysis of the Hertz model that allows to calculate the minimum possible error in the determination of E, which depends strongly on measurement noise but also on experimental parameters like spring constant and indentation depth. Scaling laws for these dependencies are analytically derived and supplemented by simulated and real indentation measurements. Our findings allow a systematic optimization of indentation experiments to increase the accuracy in the determination of E.