Actuating a curved elastic filament for bidirectional propulsion

2020 ◽  
Vol 5 (12) ◽  
Author(s):  
Zhaorong Liu ◽  
Fenghua Qin ◽  
Lailai Zhu
Keyword(s):  
Elastic Filament

scholarly journals Soft Matter Emerging Investigators Issue 2021 - "Propulsion of an elastic filament in a shear-thinning fluid at low Reynolds numbers"

Soft Matter ◽  
2021 ◽  
Author(s):  
Ke Qin ◽  
Zhiwei Peng ◽  
Ye Chen ◽  
Herve Nganguia ◽  
Lailai Zhu ◽  
...  
Keyword(s):  
Soft Matter ◽  
Reynolds Numbers ◽  
Shear Thinning ◽  
Low Reynolds Numbers ◽  
Elastic Filament ◽  
Low Reynolds ◽  
Micro Organisms ◽  
Surrounding Fluid ◽  
Shear Thinning Fluid ◽  
Flexible Appendages

Some micro-organisms and artificial micro-swimmers propel at low Reynolds numbers (Re) via the interaction of their flexible appendages with the surrounding fluid. While their locomotion have been extensively studied with...

scholarly journals Effects of thermal noise on the transitional dynamics of an inextensible elastic filament in stagnation flow

Soft Matter ◽  
2015 ◽  
Vol 11 (24) ◽  
pp. 4962-4972 ◽  
Author(s):  
Mingge Deng ◽  
Leopold Grinberg ◽  
Bruce Caswell ◽  
George Em Karniadakis
Keyword(s):  
Partial Differential Equations ◽  
Stagnation Point ◽  
Stochastic Partial Differential Equations ◽  
Continuum Model ◽  
Thermal Noise ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Stagnation Flow ◽  
Anisotropic Friction ◽  
Elastic Filament

We investigate the dynamics of a single inextensible elastic filament subject to anisotropic friction in a viscous stagnation-point flow, by employing both a continuum model represented by Langevin type stochastic partial differential equations (SPDEs) and a dissipative particle dynamics (DPD) method.

scholarly journals Microtubules soften due to cross-sectional flattening

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Edvin Memet ◽  
Feodor Hilitski ◽  
Margaret A Morris ◽  
Walter J Schwenger ◽  
Zvonimir Dogic ◽  
...  
Keyword(s):  
High Strain ◽  
Three Dimensional ◽  
Elastic Model ◽  
Softening Effect ◽  
Cross Sectional ◽  
Mechanical Compliance ◽  
Wide Range ◽  
Elastic Filament ◽  
New Interpretation ◽  
Effective Mechanical Properties

We use optical trapping to continuously bend an isolated microtubule while simultaneously measuring the applied force and the resulting filament strain, thus allowing us to determine its elastic properties over a wide range of applied strains. We find that, while in the low-strain regime, microtubules may be quantitatively described in terms of the classical Euler-Bernoulli elastic filament, above a critical strain they deviate from this simple elastic model, showing a softening response with increasing deformations. A three-dimensional thin-shell model, in which the increased mechanical compliance is caused by flattening and eventual buckling of the filament cross-section, captures this softening effect in the high strain regime and yields quantitative values of the effective mechanical properties of microtubules. Our results demonstrate that properties of microtubules are highly dependent on the magnitude of the applied strain and offer a new interpretation for the large variety in microtubule mechanical data measured by different methods.

scholarly journals Well‐Posedness and Global Behavior of the Peskin Problem of an Immersed Elastic Filament in Stokes Flow

2018 ◽  
Vol 72 (5) ◽  
pp. 887-980 ◽  
Author(s):  
Yoichiro Mori ◽  
Analise Rodenberg ◽  
Daniel Spirn
Keyword(s):  
Stokes Flow ◽  
Global Behavior ◽  
Well Posedness ◽  
Elastic Filament

Nmr relaxation in DNA. I. The contribution of torsional deformation modes of the elastic filament

Biopolymers ◽  
1982 ◽  
Vol 21 (4) ◽  
pp. 729-762 ◽  
Author(s):  
S. A. Allison ◽  
J. H. Shibata ◽  
J. Wilcoxon ◽  
J. M. Schurr
Keyword(s):  
Nmr Relaxation ◽  
Torsional Deformation ◽  
Elastic Filament ◽  
Deformation Modes

Simulation of an inhomogeneous elastic filament falling in a flowing viscous fluid

2007 ◽  
Vol 19 (1) ◽  
pp. 017113 ◽  
Author(s):  
Luoding Zhu
Keyword(s):  
Viscous Fluid ◽  
Elastic Filament

scholarly journals Instabilities and Spatiotemporal Dynamics of Active Elastic Filaments

2019 ◽  
Author(s):  
Yaouen Fily ◽  
Priya Subramanian ◽  
Tobias M. Schneider ◽  
Raghunath Chelakkot ◽  
Arvind Gopinath
Keyword(s):  
Molecular Motors ◽  
Brownian Dynamics ◽  
Linear Stability Theory ◽  
Unified Framework ◽  
Cytoskeletal Filament ◽  
Elastic Filaments ◽  
Elastic Filament ◽  
Follower Forces ◽  
Dynamics Simulations ◽  
Brownian Dynamics Simulations

Biological filaments driven by molecular motors tend to experience tangential propulsive forces also known as active follower forces. When such a filament encounters an obstacle, it deforms, which reorients its follower forces and alters its entire motion. If the filament pushes a cargo, the friction on the cargo can be enough to deform the filament, thus affecting the transport properties of the cargo. Motivated by cytoskeletal filament motility assays, we study the dynamic buckling instabilities of a two-dimensional slender elastic filament driven through a dissipative medium by tangential propulsive forces in the presence of obstacles or cargo. We observe two distinct instabilities. When the filament’s head is pinned or experiences significant translational but little rotational drag from its cargo, it buckles into a steadily rotating coiled state. When it is clamped or experiences both significant translational and rotational drag from its cargo, it buckles into a periodically beating, overall translating state. Using minimal analytically tractable models, linear stability theory, and fully non-linear computations, we study the onset of each buckling instability, characterize each buckled state, and map out the phase diagram of the system. Finally, we use particle-based Brownian dynamics simulations to show our main results are robust to moderate noise and steric repulsion. Overall, our results provide a unified framework to understand the dynamics of tangentially propelled filaments and filament-cargo assemblies.

scholarly journals Polymer-like model to study the dynamics of dynamin filaments on deformable membrane tubes

2019 ◽  
Author(s):  
Jeffrey K. Noel ◽  
Frank Noé ◽  
Oliver Daumke ◽  
Alexander S. Mikhailov
Keyword(s):  
Thermal Fluctuations ◽  
Membrane Curvature ◽  
Coarse Grained ◽  
Chain Model ◽  
Dependent Manner ◽  
Membrane Tube ◽  
Elastic Filament ◽  
Intrinsic Shape ◽  
Deformable Membrane ◽  
Dynamics Simulations

AbstractPeripheral membrane proteins with intrinsic curvature can act both as sensors of membrane curvature and shape modulators of the underlying membranes. A well-studied example of such proteins is the mechano-chemical GTPase dynamin that assembles into helical filaments around membrane tubes and catalyzes their scission in a GTPase-dependent manner. It is known that the dynamin coat alone, without GTP, can constrict membrane tubes to radii of about 10 nanometers, indicating that the intrinsic shape and elasticity of dynamin filaments should play an important role in membrane remodeling. However, molecular and dynamic understanding of the process is lacking. Here, we develop a dynamical polymer-chain model for a helical elastic filament bound on a deformable membrane tube of conserved mass, accounting for thermal fluctuations in the filament and lipid flows in the membrane. The model is based on a locally-cylindrical helix approximation for dynamin. We obtain the elastic parameters of the dynamin filament by molecular dynamics simulations of its tetrameric building block and also from coarse-grained structure-based simulations of a 17-dimer filament. The results show that the stiffness of dynamin is comparable to that of the membrane. We determine equilibrium shapes of the filament and the membrane, and find that mostly the pitch of the filament, not its radius, is sensitive to variations in membrane tension and stiffness. The close correspondence between experimental estimates of the inner tube radius and those predicted by the model suggests that dynamin’s “stalk” region is responsible for its GTP-independent membrane-shaping ability. The model paves the way for future mesoscopic modeling of dynamin with explicit motor function.

Research on performance of twin-core spun yarn and fabric

2019 ◽  
Vol 32 (3) ◽  
pp. 338-355
Author(s):  
Xuzhong Su ◽  
Xuzhong Su ◽  
Xinjin Liu
Keyword(s):  
High Temperature ◽  
Fiber Composite ◽  
Woven Fabrics ◽  
Numerical Control ◽  
Content Type ◽  
The Core ◽  
Spun Yarn ◽  
Finishing Process ◽  
Spun Yarns ◽  
Elastic Filament

Purpose As one kind of filament/staple fiber composite yarn, core spun yarn has been widely used, especially on Jeans. However, there is only one filament in the commonly used core spun yarn, such as spandex, and the performance of the one filament often is influenced during dyeing and finishing. Therefore, in the paper, twin-core spun yarns with two different filaments feeding simultaneously were spun on ring spinning frame modified by one kind of filament feeding numerical control device. The paper aims to discuss these issues. Design/methodology/approach Four kinds of twin-core spun yarns, cotton/spandex/PBT, cotton/spandex/CM800, cotton/spandex/T400, cotton/spandex/SPH with linear density 36.4tex/40D/50D were spun. For improving the covering effect of the two filaments, the filament feeding position, filament pre-drafting multiple, distance between two staple roving, designed twist factor of the core spun yarn were optimized. Findings It is shown that comparing with the core spun yarn, the breaking strength and elongation of the twin-core spun yarns are improved since the addition of another elastic filament, while the evenness is a little worse. Originality/value By using the twin-core spun yarns, corresponding knitted and woven fabrics are produced. Meanwhile, for simulating the dyeing and finishing process, the knitted fabrics were treated during the 150°C high temperature. It is shown that comparing with the fabrics produced by cotton/spandex yarn, addition of another elastic filament can improve the fabric strength and resistant and has positive effect on worsen prevention for high temperature treated fabric elastic recovery, and on change prevention during the dyeing and finishing process for fabric handle properties, and improves the fabric stability.

Forced motion of an elastic filament through a narrow tube

2015 ◽  
Vol 31 (6) ◽  
pp. 789-790 ◽  
Author(s):  
L. B. Freund
Keyword(s):  
Narrow Tube ◽  
Forced Motion ◽  
Elastic Filament
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