Self-organized swimming with odd elasticity

TL;DR

This paper explores how odd elasticity in active materials enables self-organized swimming at low Reynolds numbers, revealing stable oscillations and biased locomotion driven by non-symmetric elastic moduli.

Contribution

It demonstrates that odd elasticity can induce self-oscillating swimming and biased movement in active filaments, extending understanding of elastohydrodynamic interactions.

Findings

Odd elasticity enables stable limit cycle oscillations.

Self-organized swimming occurs in an active filament model.

Biased net locomotion arises from non-symmetric elasticity under noise.

Abstract

We theoretically investigate self-oscillating waves of an active material, which have recently been introduced as a non-symmetric part of the elastic moduli, termed odd elasticity. Using Purcell's three-link swimmer model, we reveal that an odd-elastic filament at low Reynolds number can swim in a self-organized manner and that the time-periodic dynamics are characterized by a stable limit cycle generated by elastohydrodynamic interactions. Also, we consider a noisy shape gait and derive a swimming formula for a general elastic material in the Stokes regime with its elasticity modulus being represented by a non-symmetric matrix, demonstrating that the odd elasticity produces biased net locomotion from random noise.