Researchers Discover Odd Elasticity Emerges Naturally in Disordered Chiral Active Materials
A new theoretical study shows that odd elasticity—an unusual elastic response where materials don't obey traditional symmetries—naturally arises in disordered chiral active materials through internal particle rotations. The research extends previous understanding of odd elasticity from ordered metamaterials to biological and natural systems like the cytoskeleton and bacterial flagella. This finding could help explain mechanical properties of living systems and inform design of new active materials.
Researchers have developed a theoretical model demonstrating how odd elasticity emerges in disordered chiral active materials—systems that break both time-reversal and mirror-image symmetries through microscale torque injection. Using micropolar elasticity theory with local active torques, the team found that odd elasticity naturally appears as a nonlinear effect of internal particle rotations. The study also explores the viscoelasticity of such materials when immersed in odd fluids, revealing new dynamically unstable regions driven by solid-fluid coupling and inertial effects. Notably, in the overdamped limit, bulk wave propagation can occur near these unstable regions. The work extends previous understanding of odd elasticity from ordered metamaterial structures to naturally disordered systems like biological materials, potentially explaining mechanical behaviors in the cytoskeleton, bacterial flagella clusters, and other chiral active systems found in nature.
What's missing
The study is theoretical and based on a minimal generic model; experimental validation of these predictions in actual biological or synthetic disordered chiral active materials is not discussed. The practical applications or implications for materials engineering or biological understanding remain to be explored.
What different sources said
- arXiv physicsCenter
Odd elasticity in disordered chiral active materials
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