Abstract
Equilibrium self-assembly and conventional materials processing techniques fall far short of mimicking dynamic self-actuating processes that are commonplace throughout biology. Here, to bridge the gap between living and synthetic matter, we study passive adhesive non-thermal actin fibres immersed in an active microtubule-based fluid. We show that autonomous chaotic flows power non-equilibrium fibre dynamics, thus inducing collisions, generating connections and weaving a membrane-like elastic network. The ensuing active assembly generates a hierarchy of shapes, structures and dynamical processes spanning nanometres to centimetres. Ultimately, it generates an active membrane that exhibits global limit cycles induced by a non-reciprocal coupling between deformations of the elastic membrane and the alignment axis of the nematic active fluid. Our work merges self-assembly with active matter to demonstrate self-processing materials wherein hierarchical life-like structures and dynamics emerge from an initially structureless suspension.