Elastoinertial Effects Govern Dynamic Response of Soft Hair Beds

This study investigates the dynamic mechanical properties of fluid-immersed hair beds, which are crucial for mechanosensory functions in biological systems. The research focuses on the transient rheological response of elastic hair beds to oscillatory shear flows at low to intermediate Reynolds numbers. Despite the linear behavior of individual hairs and fluid, their interaction results in a nonlinear response influenced by driving frequency and amplitude. A key finding is the identification of a crossover from a stress-lagging to a stress-leading regime, governed by fluid viscosity, inertia, and hair elasticity. This behavior is captured by a simplified rigid-beam model. Understanding these dynamics is vital for biological processes like vasodilation and ciliary remodeling, as the lag time affects mechanosensory signaling stability. The study provides a framework for optimizing dynamic information transmission in mechanotransduction.