Modeling of Spermbots in a Viscous Colloidal Suspension

Spermbots are biohybrid micromachines consisting of single sperm cells captured in artificial magnetic microstructures, and have the potential to act as autonomous tools for minimally invasive medicines and in diverse in vivo applications. This work investigates the hydrodynamic effects of the spermbots in a heterogeneous viscous medium similar to environments encountered in vivo. The propulsion of the spermbots is simulated using a numerical model based on the method of regularized Stokeslets for computing Stokes flows in the presence of immersed obstacles. It is shown that the concentration and size of these obstacles create a pressure gradient along the propulsion axis of the spermbot; hence they influence its effective net motion. In particular, the simulation results herein suggest that the forward and lateral swimming speeds of the spermbot increase with the concentration of the immersed obstacles and decrease with their size.