Active drive towards elastic spinodals

TL;DR

This paper explores how active matter systems can dynamically approach and utilize elastic spinodal regimes, leading to novel mechanical behaviors such as stress localization and force chain formation, with implications for material design.

Contribution

It extends the classical concept of spinodal states to active solids and demonstrates how these regimes can be actively accessed and exploited in nonlinear settings.

Findings

Active matter can self-drive toward elastic spinodal regimes.

Crossing elastic spinodals creates new energy wells and microstructural features.

Force channeling becomes an intrinsic microstructural characteristic.

Abstract

Active matter, exemplified by adaptive living materials such as the actomyosin cytoskeleton, can navigate material parameter space dynamically, leading to unconventional mechanical responses. In particular, it can self-drive toward elastic spinodal regimes, where inhomogeneous floppy modes induce elastic degeneracy and enable a controlled interplay between rigidity loss and recovery. Proximity to such marginal states leads to stress localization and the formation of force chains that can be actively assembled and disassembled. Here, we extend the classical notion of spinodal states to active solids and demonstrate how these extreme mechanical regimes can be actively accessed. Moreover, we show that in a nonlinear setting, crossing elastic spinodals generates new energy wells and makes force channeling an intrinsic feature of the emerging microstructure.