Regensburg 2022 – scientific programme

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BP: Fachverband Biologische Physik

BP 18: Biomaterials (joint session BP/CPP)

BP 18.3: Talk

Wednesday, September 7, 2022, 15:45–16:00, H15

Rate-Independent Hysteretic Energy Dissipation in Collagen Fibrils — Robert Magerle, •Paul Zech, Martin Dehnert, Alexandra Bendixen, and Andreas Otto — Fakultät für Naturwissenschaften, Technische Universität Chemnitz, 09107 Chemnitz, Germany

Nanoindentation data measured with an atomic force microscope on hydrated collagen fibrils above the glass transition, display a rate-independent hysteresis with return point memory. It is caused by the interplay of elastoplastic deformation during tip indentation followed by elastocapillary recovery of the indent during tip retraction. This previously unknown energy dissipation mechanism dominates at slow indentation rates, where viscous friction is negligible. A generic hysteresis model, based on force-distance data measured during one approach-retract cycle, predicts the force (output) for arbitrary indentation trajectories (input). This model describes collagen fibrils' elastic as well as their dissipative nanomechanical properties with high fidelity for a large range of tip velocities and indentation amplitudes.