Predictive Theory of Field-Directed Assembly of Anisotropic Particles

Field-directed self-assembly presents a power approach for controlling reconfigurability in colloidal and nanoparticle organizations. To date, there exists a large space of experimental systems showing that an external field can speed up the assembly process, facilitate structural reorganization, and stabilize out-of-equilibrium morphologies. However, a grand challenge in its rational design lies in the lack of a predictive theory capable of identifying the thermodynamically stable morphology. Here, we present a first-principles theory that balances entropic forces arising from particle anisotropy and dipole forces resulting from particle-field interactions to a priori predict the assembly structures, validated by both simulation and experiments. We then showcase how structural reconfiguration can be captured in our theory through the lens of tuning the relative strength of entropic versus field-mediated enthalpic interactions. Our works provide a critical bridge between equilibrium lattice prediction and non-equilibrium assembly processes, opening new avenues for predictive design of complex building blocks that can target novel and reconfigurable assemblies.