Characterizing the Non-Linear Rheology of Biopolymer Networks Using Inertio-Elastic Oscillations.

Accurately characterizing the non-linear rheological properties of materials remains a challenge. Although there exist a variety of methods to probe non-linear properties, there is no consensus regarding their unique advantages. Inertio-elastic oscillations occur naturally in rotational rheometry as a consequence of a material's elasticity and the inertia of the rheometer's bearing. We demonstrate that extending this technique to non-linear deformations provides accurate measurements of non-linear material properties. Our experiments are performed on biopolymer networks, which are well-characterized, and have dramatic non-linear properties that are biologically significant. We compare these inertio-elastic results to other standard methods of probing non-linear rheology. For fibrin networks, our measurements suggest that inertio-elastic oscillations provide the most straightforward method of distinguishing between non-linear elasticity and dissipation at any given stress. In addition, we show that inertio-elastic oscillations provide the most accurate noise-free generalization of non-linear dissipation for a viscoelastic solid. [ABSTRACT FROM AUTHOR]