Soft elastic fibers in confined flows.

Cilia, soft deformable hair-like fibers, are crucial for sensory perception, motility, nutrient uptake, transport, and filtration in the animal kingdom. While much progress has been made in understanding how cilia synchronize and achieve directional pumping, their response to environmental stresses, such as shear forces and confinement, remains

less explored. In this study, we combine microfluidic experiments and theoretical modeling to investigate the behavior of anchored elastic fibers under confined flows. We

demonstrate that nonlinear interactions between flow and fiber deformation can induce instabilities, which significantly affect the dynamics of fiber arrays. These instabilities

have implications for passive flow control in confined environments and may provide insights into the mechanisms of active ciliary pumping. Our findings contribute to a

deeper understanding of the complex interplay between soft materials and fluid flows in biological and engineered systems.