SoftBio Theory Seminar: Geometry, activity and morphing in slender elastic structures

In biological systems and engineered structures, activity can be understood as the mechanical response to internal, non-mechanical stimuli. From a continuum perspective, such internal driving can be incorporated directly into elastic models through geometric incompatibilities or non-conservative constitutive couplings. In this talk, I adopt this viewpoint to examine how phenomenological descriptions of internal activity influence the behavior of slender elastic structures.

I will first present ongoing work on morphoelastic shells derived via dimensional reduction from three-dimensional nonlinear elasticity, where incompatible in-plane and curvature stimuli drive shape changes. I will also discuss how simple mechanochemical couplings can enrich the range of accessible morphologies.

I will then focus on snap-through instabilities in slender arches with intrinsic curvature as a concrete example of structure-controlled morphing dynamics. Using asymptotic and multiple-scales analysis, I show how geometry and imperfections determine the time scale and structure of shape transitions. Although triggered mechanically, this example illustrates how intrinsic geometry and internal structure govern morphing dynamics and provides a framework that can be extended to continuum descriptions of internally driven systems.

Finally, I will briefly discuss ongoing work extending this framework to plates with non-conservative elastic couplings.

These examples illustrate how activity can be incorporated into reduced continuum descriptions of elastic morphing to understand both equilibrium configurations and dynamical evolution.