(402b) Multiscale out-of-Equilibrium Structural Evolution in Bio-Based Composites

Living things organize intricate structures across lengthscales, from the molecular to the macroscopic. Equally critical is the precise orchestration of self-generated forces which alter these configurations, coordinating locomotion, growth, regulation, and environmental response. To construct soft materials with life-like adaptive and self-organized functionalities, we must control how local, molecular-scale forces climb through lengthscales, altering structures and properties along the way.

Here, we introduce a composite fibrous network of filamentous actin and microtubules, driven out-of-equilibrium by engineered kinesin motor clusters¹. By tuning the intra- and inter-network interactions with manmade and natural crosslinkers, we prescribe how the molecular motors can re-arrange the local microstructure, and program the emergent macroscale structure and dynamics. The extraordinary structural response to motor-driven reconfiguration exhibits rich behavior reminiscent of the the time-varying structures in living cells. Amongst others, we characterize the self-assembly of onion-like asters whose underlying dynamics ensure its robust structure and demonstrate the temporal stability is encoded in the mechanical properties of the network. This work highlights the potential of a new class of functional soft materials, whose structure and dynamics cannot be obtained through traditional material engineering approaches.

1. Berezney et al., Proceedings of the National Academy of Sciences. 2022; 119 (5), e2115895119