Designing self-limiting versus bulk assembly of frustrated warped-jigsaw particles

Geometrically frustrated assembly (GFA) has been offered as a promising framework for "programming" the finite size of an assembly through its local misfit and interactions. To date, finite-size selection has been largely understood through continuum models and zero-temperature energy minimization. However, realistic self-assembly relies on attractive interactions that generically induce cohesion between "self-limiting" domains themselves, raising questions about the thermodynamic stability of such finite-sized assemblies, particularly in their low temperature ground states. In this talk, we use coarse-grained molecular dynamics simulations of a so-called ``Warped Jigsaw’’ (WJ) particle model to study particle-scale properties such as shape misfit, interaction strength, and deformability determine whether the assemble state is self-limiting, or else, and a thermodynamically unlimited bulk structure. We focus on two key aspects: First, we examine the role of weak attractive interactions between frustrated domains (i.e. finite-width ribbons of WJ particles) and find that defective or weak inter-domain binding promotes the condensation of otherwise self-limiting assemblies into bulk states at sufficiently low temperatures. Second, we explore how the design of particle interactions controls the thermodynamics and morphology of assembly: asymmetric top–bottom binding weakens inter-domain cohesion, stabilizing self-limiting strips over a broad temperature range, while higher concentrations and stronger frustration favor the emergence of branched, defect-mediated networks, an alternate bulk morphology. These results translate into key design principles for ongoing efforts to realized size-selective assembly via ``engineered misfit” in experimental systems.