Modeling depletion mediated colloidal assembly on topographical patterns.

This work reports a model and Monte Carlo simulations of excluded volume mediated interactions between colloids and topographically patterned substrates in the presence of thermosensitive depletants. The model is matched to experiments to yield density, free energy, and potential energy landscapes that quantitatively capture particle microstructures varying from immobilized non-close packed configurations to random fluid states. A numerical model of local excluded volume affects is developed to enable computation of local depletion attraction in the presence of arbitrary geometries. Our findings demonstrate a quantitative modeling method to interpret and predict how surface patterns mediate local depletion interactions, which enables the design of colloidal based materials and devices.