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BP: Fachverband Biologische Physik
BP 34: Posters - Physics of Physarum polycephalum and Other Slime Molds (Focus Session)
BP 34.4: Poster
Dienstag, 21. März 2017, 14:00–16:00, P2-OG1
Indentation Analysis of Active Viscoelastic Microplasmodia of P. polycephalum — •Adrian Fessel1, Christina Oettmeier1, Ang Wei Tech2, and Hans-Günther Döbereiner1 — 1Universität Bremen, Bremen, Deutschland — 2Nanyang Technological University, Singapore
We present an analysis of force data obtained from indentation testing of vital microplasmodia of the slime mold Physarum polycephalum. Approximating the testing scenario as a layer tied to a rigid foundation leads to an estimation of Young’s modulus at E=(16.7±7.7) kPa, which is fairly consistent for various samples and for different time-dependencies of the indentation force. We observe variation of the modulus with the characteristic oscillation of P. polycephalum. Further we find a set of superimposed decay times during repeated indentation, which can be attributed to viscoelastic effects and the porous structure of microplasmodia. We demonstrate by extending the Kelvin-Voigt model to include non-linear effects and via FEM simulations, that apparent non-linearities in the stress-strain ellipsoids can be attributed to variations of sample thickness. A detailed theoretical description of the non-linear thickness effect is given in the contribution ’Non-Linear Compliance of Elastic Layers to Indentation’ (BP 7.4).