Inertial delay of self-propelled particles

Scholz, Christian; Jahanshahi, Soudeh; Ldov, Anton; Löwen, Hartmut

doi:10.1038/s41467-018-07596-x

Cited by 180 publications

(237 citation statements)

References 56 publications

Supporting

Mentioning

214

Contrasting

Unclassified

Order By: Relevance

“…In this case healthy cells may be separated for instance from malignant cells by non-symmetric liquid shaking. Our insights about inertia driven particle propulsion might also have impact on further systems studied at finite values of the Reynolds number [53,54].…”

Section: Discussionmentioning

confidence: 90%

Engineering passive swimmers by shaking liquids

et al. 2019

View full text Add to dashboard Cite

The locomotion and design of microswimmers are topical issues of current fundamental and applied research. In addition to numerous living and artificial active microswimmers, a passive microswimmer was identified only recently: a soft, Λ-shaped, non-buoyant particle propagates in a shaken liquid of zero-mean velocity (Jo et al 2016 Phys. Rev. E 94 063116). We show that this novel passive locomotion mechanism works for realistic non-buoyant, asymmetric Janus microcapsules as well. According to our analytical approximation, this locomotion requires a symmetry breaking caused by different Stokes drags of soft particles during the two half periods of the oscillatory liquid motion. It is the intrinsic anisotropy of Janus capsules and Λ-shaped particles that break this symmetry for sinusoidal liquid motion. Further, we show that this passive locomotion mechanism also works for the wider class of symmetric soft particles, e.g. capsules, by breaking the symmetry via an appropriate liquid shaking. The swimming direction can be uniquely selected by a suitable choice of the liquid motion. Numerical studies, including lattice Boltzmann simulations, also show that this locomotion can outweigh gravity, i.e. non-buoyant particles may be either elevated in shaken liquids or concentrated at the bottom of a container. This novel propulsion mechanism is relevant to many applications, including the sorting of soft particles like healthy and malignant (cancer) cells, which serves medical purposes, or the use of non-buoyant soft particles as directed microswimmers.

show abstract

Section: Discussionmentioning

confidence: 90%

Engineering passive swimmers by shaking liquids

et al. 2019

View full text Add to dashboard Cite

show abstract

“…tive and positive rototaxis by simply altering its initial swim orientation with respect to its position in the flow field. This is made possible in the presence of inertia that is increasingly being recognized to play a pivotal role in the dynamics of microswimmers (43)(44)(45)(46). The paper is organized as follows.…”

Section: R a F Tmentioning

confidence: 99%

“…While existing studies of active matter have predominantly been focused on overdamped systems (1, 2) owing to the typical flow regime where a majority of microswimmers reside, there has been recent interest in understanding the role of inertia (56). Most notably, experimental work on macroscopic synthetic self-propelled particles are found to exhibit a nontrivial inertial delay between orientation and swim directions that can significantly affect dynamical properties of steady state (43). In addition, inertial effects can also emerge from unconventional couplings between rotational and translational degrees of freedom (44), or a consequence of the finite speed at which information can propagate in systems that exhibit collective motion (46).…”

Section: Inertial Dynamicsmentioning

confidence: 99%

Rototaxis: Localization of active motion under rotation

Zheng

Löwen

2020

Phys. Rev. Research

Self Cite

View full text Add to dashboard Cite

The ability to navigate in complex, inhomogeneous environments is fundamental to survival at all length scales, giving rise to the rapid development of various subfields in bio-locomotion such as the well established concept of chemotaxis. In this work, we extend this existing notion of taxis to rotating environments and introduce the idea of "roto-taxis" to bio-locomotion. In particular, we explore both overdamped and inertial dynamics of a model synthetic self-propelled particle in the presence of constant global rotation, focusing on the particle's ability to localize near a rotation center as a survival strategy. We find that in the overdamped regime, the swimmer is in general able to generate a self restoring active torque that enables it to remain on stable epicyclical-like trajectories. On the other hand, for underdamped motion with inertial effects, the intricate competition between self-propulsion and inertial forces, in conjunction with the rototactic torque leads to complex dynamical behavior with nontrivial phase space of initial conditions which we reveal by numerical simulations. Our results are relevant for a wide range of setups, from vibrated granular matter on turntables to microorganisms or animals swimming near swirls or vortices.biological movement | chemotaxis| microswimmers | active matter

show abstract

“…This implies that the particle essentially moves along a straight trajectory without changing its orientation [62-73]. The active particle may represent a swimming microorganism [74][75][76][77][78][79] or an artificial microrobot that can be manipulated by controlled external fields [80][81][82][83].…”

Section: System Setupmentioning

confidence: 99%

Theory of active particle penetration through a planar elastic membrane

et al. 2019

Self Cite

View full text Add to dashboard Cite

With the rapid advent of biomedical and biotechnological innovations, a deep understanding of the nature of interaction between nanomaterials and cell membranes, tissues, and organs, has become increasingly important. Active penetration of nanoparticles through cell membranes is a fascinating phenomenon that may have important implications in various biomedical and clinical applications. Using a fully analytical theory supplemented by particle-based computer simulations, the penetration process of an active particle through a planar two-dimensional elastic membrane is studied. The membrane is modeled as a selfassembled sheet of particles, uniformly arranged on a square lattice. A coarse-grained model is introduced to describe the mutual interactions between the membrane particles. The active penetrating particle is assumed to interact sterically with the membrane particles. State diagrams are presented to fully characterize the system behavior as functions of the relevant control parameters governing the transition between different dynamical states. Three distinct scenarios are identified. These compromise trapping of the active particle, penetration through the membrane with subsequent self-healing, in addition to penetration with permanent disruption of the membrane. The latter scenario may be accompanied by a partial fragmentation of the membrane into bunches of isolated or clustered particles and creation of a hole of a size exceeding the interaction range of the membrane components. It is further demonstrated that the capability of penetration is strongly influenced by the size of the approaching particle relative to that of the membrane particles. Accordingly, active particles with larger size are more likely to remain trapped at the membrane for the same propulsion speed. Such behavior is in line with experimental observations. Our analytical theory is based on a combination of a perturbative expansion technique and a discrete-tocontinuum formulation. It well describes the system behavior in the small-deformation regime. Particularly, the theory allows to determine the membrane displacement of the particles in the trapping state. Our approach might be helpful for the prediction of the transition threshold between the trapping and penetration in real-space experiments involving motile swimming bacteria or artificial active particles.

show abstract

Inertial delay of self-propelled particles

Cited by 180 publications

References 56 publications

Engineering passive swimmers by shaking liquids

Engineering passive swimmers by shaking liquids

Rototaxis: Localization of active motion under rotation

Theory of active particle penetration through a planar elastic membrane

Contact Info

Product

Resources

About