Fluid elasticity can enable propulsion at low Reynolds number

Experimental Investigations of Elastic Tail Propulsion At Low Reynolds Number

On self-propulsion of micro-machines at low Reynolds number: Purcell's three-link swimmer

Using slender-body hydrodynamics in the inertialess limit, we examine the motion of Purcell’s swimmer, a planar, fore–aft-symmetric three-link flagellum or propulsive mechanism that translates by alternately moving its front and rear segments. Purcell (1976) concluded via symmetry arguments that the net displacement of such a swimmer must follow a straight line, but the direction and other deta...

Magnetically actuated propulsion at low Reynolds numbers: towards nanoscale control.

Significant progress has been made in the fabrication of micron and sub-micron structures whose motion can be controlled in liquids under ambient conditions. The aim of many of these engineering endeavors is to be able to build and propel an artificial micro-structure that rivals the versatility of biological swimmers of similar size, e.g. motile bacterial cells. Applications for such artificia...

Low-Reynolds-number swimming at pycnoclines.

Microorganisms play pivotal functions in the trophic dynamics and biogeochemistry of aquatic ecosystems. Their concentrations and activities often peak at localized hotspots, an important example of which are pycnoclines, where water density increases sharply with depth due to gradients in temperature or salinity. At pycnoclines organisms are exposed to different environmental conditions compar...

Quiet swimming at low Reynolds number.

The stresslet provides a simple model of the flow created by a small, freely swimming and neutrally buoyant aquatic organism and shows that the far field fluid disturbance created by such an organism in general decays as one over distance squared. Here we discuss a quieter swimming mode that eliminates the stresslet component of the flow and leads to a faster spatial decay of the fluid disturba...