Mechanical sensing of particles enhanced by controlled agitation

Marine organisms generate unsteady flow patterns around their body, but the effects on mechanical sensing and prey detection are not fully understood. Here we report a simplified model designed to elucidate what information becomes available to an organism equipped with mechanical sensors in highly dynamic environments. The model reveals that generating strong shear or strain around a small particle distorts the flow field, which could be sensed to infer the exact size and location of the particle. The basic physical principle relies on the particle's resistance to strain, contrary to the particle’s deformation or translation relative to the sensors as commonly assumed in past models of hydrodynamic imaging. Our findings imply that even inert particles can be detected remotely by carefully agitating their fluid environment. This offers a possible mechanism for prey detection in the dark depths of the world’s oceans.