Activated barrier crossing dynamics of a Janus particle carrying cargo

Abstract

We numerically study the escape kinetics of a self-propelled Janus particle, carrying a cargo, from a meta-stable state. We assume that the cargo is attached to the Janus particle by a flexible harmonic spring. We take into account the effect of the velocity field created in the fluid due to movements of the dimer's components, by considering a space-dependent diffusion tensor (Oseen tensor). Our simulation results show that the synchronization between barrier crossing events and the rotational relaxation process can enhance the escape rate to a large extent. Also, the load carrying capability of a Janus particle is largely controlled by its rotational dynamics and self-propulsion velocity. Moreover, the hydrodynamic interaction, conspicuously, enhances the escape rate of the Janus-cargo dimer. The most important features in escape kinetics have been justified based on analytic arguments.

Escape kinetics of self-propelled particles from a circular cavity

“…maximises the switching rate between two wells. This feature was observed in the earlier studies for entropic as well as energetic barrier crossing dynamics of active species [43,48,49].…”

“…Several recent studies have been devoted to explore different aspects of the escape kinetics of self-propelled particles from metastable states [12,43,[47][48][49][50][51][52][53][54][55]. Aiming at nano-technological and biomedical applications, the escape dynamics of self-propelled particles from a compartment of entropic channels has been investigated in Refs [12,43].…”

“…Their study offers an analytical expression of escape rate in the small and large limits of rotational relaxation time, which can be adjusted by tuning the particle size. Based on the extensive numerical simulation, the barrier crossing dynamics has further been extended to active Brownian particles (ABPs) carrying cargo [49]. This study shows that synchronisation between barrier crossing events and the rotational relaxation process can enhance the escape rate to a large extent.…”

Designing circle Swimmers: Principles and strategies

“…From biological motors, bacteria to synthetic active colloids, a large amount of microswimmers have received many attentions due to the nontrivial dynamical behaviors forbidden in equilibrium systems [6][7][8][9][10][11]. The abundant nonequilibrium properties of microswimmers make them of great importance in acting as carriers for cargo delivery in the realm of natural or man-made micromachines, which are of significant interest for applications such as drug delivery, biosensing, or shuttle-transport of the emulsion droplets and living cells [12][13][14][15][16]. Recently, great efforts have been made to develop series of synthetic microswimmers to meet the specific conditions required for cargo delivery.…”

Optimal navigation strategies for active particles

“…Likewise, the life of bacteria rests upon their chemotactic navigation tasks towards food and away from toxins [5,6]. In the flourishing realm of synthetic microswimmers [7][8][9][10][11], in turn, controlling the choice of the swimming direction is crucial for technological and medical applications like delivering drugs [12,13] or other cargo [14][15][16][17] towards a prescribed target. Here, the swimming direction can be controlled via external chemical [6,[18][19][20] or electromagnetic fields [16] but also by feedback-based strategies [21][22][23].…”