Numerical study on the steady self-diffusiophoresis of a spherical Janus particle in a Brinkman medium

The locomotion of a self-diffusiophoretic Janus particle in a complex medium is crucial for biomedical applications. In this work, the self-propulsion of a spherical Janus particle in a Brinkman medium is studied by developing a coupled mathematical model integrating solute diffusion with Brinkman flow equations. Notably, the law of the particle's self-diffusiophoretic speed, power dissipation, and swimming efficiency are investigated with the surface coverage and swimming resistance. Numerical results show that the distribution of propulsion speed is symmetric regarding the surface coverage, and the relative propulsion speed is independent of surface coverage. The relative power dissipation is increased significantly with swimming resistance when the swimming resistance exceeds a critical value. Additionally, swimming efficiency demonstrates non-monotonic behavior with variations of resistance. Our numerical results may further guide the design of synthetic active particles capable of efficient operation within complex physiological environments.