Topologically Protected Transport of Cargo in a Chiral Active Fluid Aided by Odd-Viscosity-Enhanced Depletion Interactions

The discovery of topological edge states that unidirectionally propagate along the boundary of system without backscattering has enabled the development of new design principles for material or information transport. Here, we show that the topological edge flow supported by the chiral active fluid composed of spinners can even robustly transport an immersed intruder with the aid of the spinner-mediated depletion interaction between the intruder and boundary. Importantly, the effective interaction significantly depends on the dissipationless odd viscosity of the chiral active fluid, which originates from the spinning-induced breaking of time-reversal and parity symmetries, rendering the transport controllable. Our findings propose a novel avenue for robust cargo transport and could open a range of new possibilities throughout biological and microfluidic systems.

Automated summary

The discovery of topological edge states that propagate unidirectionally along the boundary of a system without backscattering has led to new design principles for material or information transport. This study demonstrates that topological edge flow supported by chiral active fluid composed of spinners can robustly transport an immersed intruder through spinner-mediated depletion interaction. The effective interaction depends significantly on the dissipationless odd viscosity of the chiral active fluid, making the transport controllable and proposing a novel avenue for robust cargo transport in biological and microfluidic systems.