Active control of active fluids

Active matter systems feature discrete particles that can self-propel by converting stored or ambient free energy into motion. This mechanism results in an array of novel structural and transport phenomena that are not observed in their equilibrium counterparts. Informed by our recent work on excess entropy scaling relationships for a simple model of active fluids, in this work, we investigate strategies for driving an active fluid to a particular non-equilibrium state in which the fluid has a specified value for its self-diffusion coefficient. These strategies leverage the degree of activity of active particles as the key control parameter. We calibrate and refine our strategies within a testbed of automated molecular-dynamics simulations, with variations in model for and extent of activity, volume fraction of active particles, and interaction between inactive and active particles. We also briefly discuss strategies for accelerated sampling of transport coefficients, which aid in our efforts to achieve on-the-fly control of fluid transport properties.