Sticky surface: sphere–sphere adhesion dynamics

Sircar, Sarthok; Younger, John G.; Bortz, David M.

doi:10.1080/17513758.2014.942394

Cited by 14 publications

(7 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, recent experiments and simulations have shown that tangential frictional forces between rough, and otherwise stochastic particles, are probably the origin of the shear-thickening behaviour of many materials [1,2]. Other studies demonstrate that sticky tethers attached to particle surfaces can change their dynamics [3,4]. Since one promising method of creating colloids with programmable interactions is to coat them with strands of DNA [5][6][7][8], which could impede their relative sliding, this could have major implications for their assembly pathways and hence structures that can be formed by selfassembly.…”

mentioning

confidence: 99%

Stochastic disks that roll

Holmes-Cerfon

2016

Phys. Rev. E

View full text Add to dashboard Cite

We study a model of rolling particles subject to stochastic fluctuations, which may be relevant in systems of nano-or micro-scale particles where rolling is an approximation for strong static friction. We consider the simplest possible non-trivial system: a linear polymer of three of discs constrained to remain in contact, and immersed in an equilibrium heat bath so the internal angle of the polymer changes due to stochastic fluctuations. We compare two cases: one where the discs can slide relative to each other, and the other where they are constrained to roll, like gears. Starting from the Langevin equations with arbitrary linear velocity constraints, we use formal homogenization theory to derive the overdamped equations that describe the process in configuration space only. The resulting dynamics have the formal structure of a Brownian motion on a Riemannian or subRiemannian manifold, depending on if the velocity constraints are holonomic or non-holonomic. We use this to compute the trimer's equilibrium distribution both with, and without, the rolling constraints. Surprisingly, the two distributions are different. We suggest two possible interpretations of this result: either (i) dry friction (or other dissipative, nonequilibrium forces) changes basic thermodynamic quantities like the free energy of a system, a statement that could be tested experimentally, or (ii) as a lesson in modeling rolling or friction more generally as a velocity constraint when stochastic fluctuations are present. In the latter case, we speculate there could be a "roughness" entropy whose inclusion as an effective force could compensate the constraint and preserve classical Boltzmann statistics. Regardless of the interpretation, our calculation shows the word "rolling" must be used with care when stochastic fluctuations are present.Particles that live on the nano-or microscale commonly have short-ranged interactions, so their surfaces come close enough that surface frictional effects may be important. For example, recent experiments and simulations have shown that tangential frictional forces between rough, and otherwise stochastic particles, are probably the origin of the shear-thickening behaviour of many materials [1,2]. Other studies demonstrate that sticky tethers attached to particle surfaces can change their dynamics [3,4]. Since one promising method of creating colloids with programmable interactions is to coat them with strands of DNA [5][6][7][8], which could impede their relative sliding, this could have major implications for their assembly pathways and hence structures that can be formed by selfassembly. On these scales it is extremely difficult to measure the particles' rotational degrees of freedom, so one must resort to indirect methods to determine whether tangential frictional forces are present [9,10]. Therefore, it would be highly desirable to find a simpler way to quantify these forces, via macroscopic measurements of spatial positions only.While the mascroscopic effect of dry friction has been studied in detail i...

show abstract

mentioning

confidence: 99%

Stochastic disks that roll

Holmes-Cerfon

2016

Phys. Rev. E

View full text Add to dashboard Cite

show abstract

“…setting V = 0 in Eqn. (3, 11)), thus causing the binders to adhere normal to the binding surface [32]. Similarly, cell-cell adhesion in the absence of surface charges have been reported in the medical literature as well [33].…”

Section: Conclusion and Discussionmentioning

confidence: 93%

Impact of flow on ligand-mediated bacterial flocculation

Sircar¹,

Bortz²

2013

Mathematical Biosciences

Self Cite

View full text Add to dashboard Cite

To understand the adhesion-fragmentation dynamics of bacterial aggregates (i.e., flocs), we model the aggregates as two ligand-covered rigid spheres. We develop and investigate a model for the attachment/detachment dynamics in a fluid subject to a homogeneous planar shear-flow. The binding ligands on the surface of the flocs experience attractive and repulsive surface forces in an ionic medium and exhibit finite resistance to rotation (via bond tilting). For certain range of material and fluid parameters, our results predict a nonlinear or hysteretic relationship between the binding/unbinding of the floc surface and the net floc velocity (translational plus rotational velocity). We show that the surface adhesion is promoted by increased fluid flow until a critical value, beyond which the bonds starts to yield. Moreover, adhesion is not promoted in a medium with low ionic strength, or flocs with bigger size or higher binder stiffness. The numerical simulations of floc-aggregate number density studies support these findings.

show abstract

“…The attraction between the LM droplets and cells in solution was calculated through the DLVO approach (Figure 6a; Figure S12, Supporting Information). W(D) is the sum of the repulsive Coulombic forces W c (D) and attractive Van der Waals forces W VdW (D), as a function of the LM droplet-cell separation distance and can be described simply by the following equation: [42] W(D) W (D) W (D)…”

Section: Proposed Explanation Of Lm Droplet Wrinkling Upon Cell Contactmentioning

confidence: 99%

Interactions between Liquid Metal Droplets and Bacterial, Fungal, and Mammalian Cells

Cheeseman

Elbourne

Gangadoo

et al. 2022

Adv Materials Inter

View full text Add to dashboard Cite

Liquid metals (LMs) have emerged as novel materials for biomedical applications. Here, the interactions taking place between cells and LMs are reported, presenting a unique opportunity to explore and understand the LM‐biological interface. Several high‐resolution imaging techniques are used to characterize the interaction between droplets of gallium LM and bacterial, fungal, and mammalian cells. Adhesive interactions between cells and LM droplets are observed, causing deformation of the LM droplet surface, resulting in surface wrinkling and in some cases, breakage of the native oxide layer present on the LM droplet surface. In many instances, the cell wall deforms to intimately contact the LM droplets. Single‐cell force spectroscopy is performed to quantify the adhesion forces between cells and LM and characterize the nature of the adhesion. It is proposed that the flexible nature of the cell enables multiple adhesion sites with the LM droplets, imparting tensile forces on the LM droplet surface, which results in surface wrinkling on the LM droplets due to their liquid nature. Molecular dynamics simulations also suggest that flexible biomolecules on the cell surface can disrupt the Ga2O3 layer formed at the LM droplet surface. This study reveals a unique biointerfacial interaction and provides insights into the mechanisms involved.

show abstract

Sticky surface: sphere–sphere adhesion dynamics

Cited by 14 publications

References 44 publications

Stochastic disks that roll

Stochastic disks that roll

Impact of flow on ligand-mediated bacterial flocculation

Interactions between Liquid Metal Droplets and Bacterial, Fungal, and Mammalian Cells

Contact Info

Product

Resources

About