Short and long-range cyclic patterns in flows of DNA solutions in microfluidic obstacle arrays

Ström, Oskar E.; Beech, Jason P.; Tegenfeldt, Jonas O.

doi:10.1039/d2lc01051h

Cited by 4 publications

(32 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 we can see how the symmetry of the macroscopic wave pattern is broken for the array with triangular pillars. As opposed to the case of circular pillars which generates two types of waves with orientations mirrored around the axis along the device channel with equal probability, as previously reported, 19 only one type of wave dominates for each ow direction when we break the lateral symmetry using the triangular pillars. This is in contrast to the spontaneous lateral symmetry breaking around circular obstacles that lacks any preferential direction.…”

Section: Macroscopic Wavesmentioning

confidence: 67%

“…As a solution of λ phage DNA at high concentration exceeding the overlap concentration as in our previous work 19 is forced to flow through the pillar array at various applied pressures, the fluorescence images give us information about the local concentration of the DNA as it varies over space and time. We observe several phenomena with large qualitative differences immediately apparent in the two flow directions.…”

Section: Resultsmentioning

confidence: 89%

“…We have subsequently shown that the formation of these waves depends to a large degree on the viscoelastic properties of the uid and the order of the pillar array, with large scale ow patterns or waves absent in arrays where the position of each pillar has been randomly perturbed. 19 Symmetry plays an important role in this context. DLD is by its nature asymmetric.…”

Section: Introductionmentioning

confidence: 99%

“…There is thus a strong interest in understanding the origin of the instabilities as well as in the development of strategies for controlling them. While randomization of the pillar structure has been shown to suppress the instabilities, 19,32 for certain cases a randomization can enhance instabilities, 33 and for some applications it may be unsuitable where a regular array is required for optimal operation. 7,13 Other approaches for suppression involve careful channel design, [34][35][36] so borders 37 and ow modulation.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper we explore the role of the symmetry of the array pillars on the macroscopic waves that we have reported previously. 19 We then use what we have learnt to show proof of principle of prospective applications in terms of stabilized flows, mixing and rectified flows.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Using symmetry to control viscoelastic waves in pillar arrays

Beech,

Ström,

Turato

et al. 2023

RSC Adv.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Macroscopic Wavesmentioning

confidence: 67%

Section: Resultsmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Using symmetry to control viscoelastic waves in pillar arrays

Beech,

Ström,

Turato

et al. 2023

RSC Adv.

Self Cite

View full text Add to dashboard Cite

show abstract

A web of sticky strands: how localized stress controls spatio-temporal fluctuations in viscoelastic flows through a lattice of obstacles

Mokhtari,

Quintard,

Davit

2024

J. Fluid Mech.

View full text Add to dashboard Cite

Recent microfluidic experiments have evidenced complex spatio-temporal fluctuations in low-Reynolds-number flows of polymer solutions through lattices of obstacles. However, understanding the nonlinear physics of such systems remains a challenge. Here, we use high performance simulations to study viscoelastic flows through a hexagonal lattice of cylindrical obstacles. We find that structures of localized polymer stress – in particular birefringent strands – control the stability and the dynamics. We first show that, at steady state, strands act as a web of sticky flow barriers that induce channelization, multistability and hysteresis. We then demonstrate that a spontaneous destabilization of the strands drives the transition to unsteady flow with regimes of self-sustained oscillations, travelling waves and strand pulsations. We further show that these pulsations, which result from the destabilization of envelope patterns of stress with strands wrapped around multiple obstacles, are integral to the transition towards elastic turbulence in our two-dimensional simulations. Our study provides a new perspective on the role of birefringent strands and a framework for understanding experimental observations. We anticipate that it is an important step towards unifying existing interpretations of the nonlinear physics of viscoelastic flows through complex structures.

show abstract

Mixing performance of an expansive mixer on viscoelastic solutions under alternating current electric field

Wang,

Xu,

2023

Physics of Fluids

View full text Add to dashboard Cite

Development of effective technologies for mixing viscoelastic solutions with reagents is still a challenge, which plays an important role in the fields of disease diagnosis, water desalination, and immunoassay. The purpose of this paper is to numerically study the mixing performance of an expansive mixer on the viscoelastic solution under the impact of an alternating current (AC) electric field through the analyzation of mixing efficiency, the concentration distribution, and average outlet velocity. A poly acrylic acid (PAA) water solution with different concentrations characterized by the Oldroyd-B constitutive model is used as a mixed medium, and an open-source toolbox called rheoTool based on finite volume algorithm is applied to solve the governing equations. We quantitatively determine the mixing efficiency for different PAA concentrations, AC electric field strengths, and frequencies and compare the mixing efficiency created by AC and direct current (DC) electric fields. Our investigation indicates that the mixing efficiency of the mixer diminishes with the PAA concentrations but enhances with the AC electric field strengths for a relatively high polymer concentration, and AC electric fields with different frequencies lead to a larger mixing efficiency than DC electric fields for a low polymer concentration. Additionally, the influence of the model parameters on the average outlet velocity and concentration distribution is discussed at length. Our numerical simulation results show that the mixer has an excellent mixing performance for both Newtonian and viscoelastic solutions, with a mixing efficiency of more than 99% at a low polymer concentration and a stable outflow velocity.

show abstract

Short and long-range cyclic patterns in flows of DNA solutions in microfluidic obstacle arrays

Abstract: We observe regular patterns emerging across multiple length scales with high-concentration DNA solutions in microfluidic pillar arrays at low Reynolds numbers and high Deborah. Interacting vortices between pillars lead to...

Cited by 4 publications

References 62 publications

Using symmetry to control viscoelastic waves in pillar arrays

Using symmetry to control viscoelastic waves in pillar arrays

A web of sticky strands: how localized stress controls spatio-temporal fluctuations in viscoelastic flows through a lattice of obstacles

Mixing performance of an expansive mixer on viscoelastic solutions under alternating current electric field

Contact Info

Product

Resources

About