Competing instabilities reveal how to rationally design and control active crosslinked gels

This paper investigates how active stresses from molecular motors influence the large-scale mechanics of a biomimetic active crosslinked gel. Experiments and theory demonstrate that the gel's emergent properties depend on its microscopic components. An extensile nematic elastomer exhibits two distinct activity-driven instabilities: in-plane bending and out-of-plane buckling, depending on composition. Molecular motors have a dual role, fluidizing or stiffening the gel based on ATP concentration. The study provides estimates for active gel theory parameters and demonstrates in situ control of instability direction using light-activable motor proteins.

Bibi Najma, Minu Varghese, Lev Tsidilkovski, Linnea Lemma, Aparna Baskaran, Guillaume Duclos