2025/04/11 by He, Mengfei, Cho, Sungkyu, Dafflisio, Gianna +2
#FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.2504.08248
Soft valves serve to modulate and rectify flows in complex vasculatures across the tree of life, e.g. in the heart of every human reading this. Here we consider a minimal physical model of the heart mitral valve modeled as a flexible conical shell capable of flow rectification via collapse and coaptation in an impinging (reverse) flow. Our experiments show that the complex elastohydrodynamics of closure features a noise-activated rectification mechanism. A minimal theoretical model allows us to rationalize our observations while illuminating a dynamical bifurcation driven by stochastic hydrodynamic forces. Our theory also suggests a way to trigger the coaptation of soft valves on demand, which we corroborate using experiments, suggesting a design principle for their efficient operation.