Which interactions dominate in active colloids

摘要: Despite mounting evidence that the same gradients, which active colloids use for swimming, induce important cross-interactions (phoretic interactions), they are still ignored in most many-body descriptions, perhaps to avoid complexity and a zoo of unknown parameters. Here we derive simple model, reduces phoretic far-field interactions pair-interaction whose strength is mainly controlled by one genuine parameter (swimming speed). The model suggests generically autophoretic (unless effective screening fields strong) should dominate over hydrodynamic typical case half-coating moderately nonuniform surface mobilities. Unlike standard minimal models, but accordance with canonical experiments, our predicts dynamic clustering at low density. This can emerge from interplay screened attractions diffusion.