Temperature-dependent shear moduli in shape-based models of dense tissue

The collective mechanical properties of groups of cells play a key role in governing their biological function. Many simplified models of dense tissue map complex cellular behaviors – such as cellular motility – onto an effective temperature characterizing the state of the system. While we have understand how temperature influences properties in ordinary disordered materials (e.g., the variation of viscosity in a cooling fluid), it remains uncertain if dense cellular materials exhibit similar qualitative behaviors in response to cellular activity. In this work we investigate the temperature dependence of the shear modulus in the Voronoi cell model—a computational shape-based model often used to describe epithelial sheets. Unlike conventional disordered systems, we show that in this model the shear modulus is surprisingly sensitive to the effective temperature of the system. We further establish a connection between this temperature-dependent shear modulus and the dynamics of cell rearrangements in the system.