Modeling of Spermbots in a Viscous Colloidal Suspension

Abstract

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.

Micromotor-mediated sperm constrictions for improved swimming performance

“…In the present work, we focus on micromotors, which are used for the transport of single sperm cells. Tubular microstructures, fabricated either by rolling up nanomembranes [ 33 ], maskless lithography [ 60 ] or two-photon photolithography [ 24 , 25 ], have been used for this purpose. Even though coupling of sperm cells to such artificial components results in a poor swimming performance when compared to freely swimming cells, it offers several advantages.…”

Nano/Micromotors in Active Matter

“…Biocompatibility, efficient locomotion in the low Reynolds number flow and manipulability make sperm cells become an ideal power source for NMMs [70]. The most common sperm-based NMMs are composed of well-designed microcap and the sperm cell [13,[71][72][73][74] (Figure 6). The microcap provides the object for functionalizing the NMM, while the sperm cell serves as the motor for the power.…”

The emerging technology of biohybrid micro-robots: a review

“…[55]); c spermbots consisting of single sperm cells captured in artificial magnetic microstructures (reproduced with permission Ref. [131]); d a method of manufacturing a biological robot composed of macrophages (reproduced with permission Ref. [133]) the light-responsive muscle obtained by ChR2 genetically engineered fruit fly larvae [55], as shown in Fig.…”

“…In addition to the muscle tissue obtained from animals such as larvae, sperm is also a biomaterial that has attracted attention because of its extraordinary motion performance. Khalil et al [131] studied the hydrodynamic effects of a sperm robot composed of bull sperm cells and microtubules (shown in Fig. 5c) in a heterogeneous viscous medium similar to the in vivo environment.…”