Emergent collective dynamics of microrobotic swarms in viscoelastic media: a computational perspective.

Microrobotic swarms are promising candidates for targeted drug delivery in complex physiological environments, including blood, mucus, and extracellular matrices. In such biomedical scenarios, collective motion is strongly influenced by low-Reynolds-number drag, crowding, confinement, viscoelasticity, and non-Newtonian rheology. This article envisages a mechanics-based computational framework for microrobotic swarms in viscoelastic (gel-like) media. Starting from Langevin dynamics, we derive the overdamped description appropriate for microscale agents and extend it to active Brownian particles with self-propulsion, local alignment, and short-range interparticle interactions. Cohesive and purely repulsive collective regimes are represented through Lennard-Jones and Weeks-Chandler-Andersen potentials, respectively. To model gel-like rheology, we introduce a fractional Kelvin-Voigt description of drag that incorporates power-law memory effects. The resulting stochastic dynamics are mapped to an explicit Euler-Maruyama algorithm with truncated-history fractional convolution, documented stabilizers, and diagnostic observables for polarization, clustering, trajectories, and transport. Beyond the model itself, the present study synthesizes recent work on bacterial living fluids, externally driven colloidal and microrobotic swarms, fish-school hydrodynamics, neural-network control of collective patterns, and cross-scale magnetic catheter-swarm thrombus removal. That microrobotic-swarm transport in biomedical media should not be treated only as a soft-matter problem is the primary takeaway. We believe that it is rather a coupled mechanics problem in which propulsion, interaction, memory, disorder, hydrodynamic communication, and clinical deliverability must be taken into consideration. At the same time, the preliminary simulations suggest a practically important biomedical trend: whereas Newtonian transport is more prone to collective aggregation, viscoelastic transport can preserve a more distributed swarm morphology, which is encouraging for controllable delivery, broader spatial coverage, and aggregation-resistant payload transport in complex bodily fluids.