Motile creases act as information bottlenecks in folded ciliary flocks

Self-folding materials have been widely investigated in both biological active matter and engineered systems. However, the programmability and robustness of self-folding remains an open problem. Trichoplax adhaerens is a sheet-like basal animal which exhibits robust self-folding and unfolding driven by collective ciliary activity coupled to a rigid substrate. Here, we study the active stochastic crease lines that emerge during this behavior. We find that creases in T. adhaerens form topologically complex, dynamic networks that evolve on second timescales, effectively compartmentalizing the animal’s cilia-substrate contact domain into distinct patches. Creases are observed to undergo unit operations, such as tip merging, which remodel this contact domain. Through cilia-resolved imaging and optic flow analysis, we show that creases act as self-limiting defects that locally disrupt elastic coupling of cilia, acting as information bottlenecks in the ciliary field to enable robust unfolding behavior. These findings reveal a novel class of active origami dynamics driven by distributed ciliary activity in which crease lines are motile in the material’s frame of reference, suggesting new design principles for engineered self-folding systems and active-matter origami.