Propulsion via flexibility in shear-thinning fluids*

In the low Reynolds number regime, flexibility can be exploited to enable propulsion via the interaction of an elastic body and its surrounding fluid. Biological fluids such as blood and mucus are typically shear-thinning. However, the impact of this ubiquitous non-Newtonian rheology on elastohydrodynamic propulsion remains largely unknown. Here we consider a minimal model to examine how shear-thinning viscosity could modify the fluid-structure interaction and hence the propulsion performance. The results may be useful for the design of artificial micro-propellers in biological fluids.