Seminar - SCM

Living systems offer a fundamentally different perspective on materials capable of function and adaptation. Unlike conventional engineering materials, where rigidity arises from internal architectures at equilibrium and is set by a stable energy minimum, living materials operate far from equilibrium. Sustained by internal forcing and environmental feedback, they generate rigidity dynamically rather than inheriting it from a pre-designed architecture. Their robustness lies in persisting under environmental fluctuations and adapting to changing loads. Rather than residing in stable equilibrium states, these systems operate near marginal stability—at the edge of rigidity—where stiffness is selectively lost, enabling strong responsiveness to perturbations and giving rise to an emergent notion of rigidity.
 

In this talk, I will present a continuum description of such active materials, with the actomyosin cytoskeleton as a prototypical system. Active constituents generate and sense contractile forces, and their interplay with soft elastic modes drives the system toward marginally stable states. Instead of collapse, these soft modes self-organize stress (and material density) into evolving networks of lower-dimensional force-bearing structures—force chains (in 2D and 3D) and force sheets (in 3D)—which sustain the applied load while remaining highly reconfigurable.

Building on this framework, I will outline ongoing and future directions toward disordered, non-equilibrium metamaterials capable of self-healing through defect mobilization or crack closure, and potentially self-replication. I will also discuss how these effects may influence the mechanics of thin sheets.