Open-Channel Microfluidics: Fundamentals and Applications

171 Pages·2019·36.559 MB·English

by  Jean Berthier, Ashleigh B. Theberge, Erwin Berthier

Open-Channel Microfluidics
Fundamentals and applications

Open-Channel Microfluidics
Fundamentals and applications
Jean Berthier, Ashleigh B Theberge and Erwin Berthier
University of Washington, Washington, USA
Morgan & Claypool Publishers
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ISBN 978-1-64327-664-9(ebook)
ISBN 978-1-64327-661-8(print)
ISBN 978-1-64327-662-5(mobi)
DOI 10.1088/2053-2571/ab21ca
Version:20190801
IOPConcisePhysics
ISSN2053-2571(online)
ISSN2054-7307(print)
AMorgan&ClaypoolpublicationaspartofIOPConcisePhysics
PublishedbyMorgan&ClaypoolPublishers,1210FifthAvenue,Suite250,SanRafael,CA,
94901,USA
IOPPublishing,TempleCircus,TempleWay,BristolBS16HG,UK
To Noam, Eden, Mila and Myron.

Contents
Foreword xi
Acknowledgments xii
Author biographies xiii
Nomenclature xv
Introduction: open-channel microfluidics and open microfluidics xvii
1 Capillarity theoretical basis 1-1
1.1 Liquid surface tension 1-1
1.2 Laplace pressure 1-2
1.3 Liquid–liquid surface tension 1-4
1.4 Contact with solid surface: Young’s law 1-5
1.5 Neumann’s construction 1-6
1.6 Work of adhesion, work of cohesion and the Young–Dupré equation 1-8
1.7 Solid surface energy: Zisman’s approach 1-9
1.7.1 Using Young’s law 1-9
1.7.2 Using Zisman’s plot 1-10
1.8 Wetting and pinning 1-14
1.8.1 Wetting 1-14
1.8.2 Pinning and canthotaxis 1-14
1.9 Wenzel law 1-17
1.10 Cassie–Baxter law 1-18
1.11 Capillary rise 1-20
1.12 Marangoni convection 1-21
References 1-22
2 Condition for capillary flow in open channels 2-1
2.1 Spontaneous capillary flow in a monolithic channel 2-1
2.2 Spontaneous capillary flow in composite open channels: 2-2
the generalized Cassie condition
2.3 Enhanced open capillary flows 2-3
2.3.1 Constant additional inlet pressure 2-3
2.3.2 Overfilled reservoir: initial additional Laplace pressure 2-6
Conclusions 2-10
References 2-10
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Open-ChannelMicrofluidics
3 Flow dynamics in open channels 3-1
3.1 Background: spontaneous capillary flow in composite, 3-1
closed channels of arbitrary uniform cross section
3.2 Flow dynamics in open micro-channels of uniform cross section 3-9
3.3 Flow dynamics in open micro-channels of variable cross sections 3-12
3.3.1 Sudden constriction and enlargements 3-12
3.3.2 Sudden enlargement with pinning: open capillary valves 3-14
3.3.3 Progressive enlargements 3-15
3.3.4 Capillary pumps 3-16
3.3.5 Filters 3-18
3.3.6 One-way wicking 3-18
3.4 The capillary dynamics of non-Newtonian fluids 3-18
3.4.1 Shear-thinning fluids 3-20
3.4.2 The case of whole blood 3-21
References 3-23
4 Open-channel geometries 4-1
4.1 Rectangular channels 4-1
4.2 Rectangular channels with imperfect corners 4-7
4.3 Rounded channels 4-8
4.4 Semi-cylindrical channel 4-13
4.5 Suspended channels 4-13
4.6 Rails 4-16
4.7 Embossed channels 4-20
4.8 Fiber bundles and flow caging 4-21
4.9 Capillary rise and uphill open capillary flows 4-24
4.10 Capillary networks 4-27
4.10.1 Example #1 4-29
4.10.2 Example #2 4-31
4.10.3 Capillary flow after a bypass or a derivation 4-31
Conclusion 4-36
References 4-37
5 Capillary filaments 5-1
5.1 Capillary filaments: the Concus–Finn condition 5-1
5.2 The case of V-grooves 5-2
5.3 Capillary filaments in open-channel turns 5-3
viii
Open-ChannelMicrofluidics
5.4 Capillary filaments in non-uniform channels 5-5
5.5 Detached capillary filaments 5-6
5.6 Metastable capillary filaments 5-8
5.7 Capillary filaments driving SCF 5-11
5.8 Dynamics of capillary filaments 5-12
5.9 Drying of capillary filaments 5-13
5.10 Capillary filaments stopped by rounded wedges 5-13
Conclusion 5-17
References 5-18
6 Two-phase open-channel capillary flows 6-1
6.1 Introduction 6-1
6.2 Plugs in uniform cross section open channels 6-1
6.2.1 Quasi steady state approach: SCF condition in 6-2
the presence of plugs
6.2.2 Plugs dynamics in open-channel capillary flow 6-5
6.2.3 Conclusions 6-10
6.2.4 Capillary wagons 6-11
6.3 Bypasses and bifurcations 6-11
6.3.1 Bifurcations 6-11
6.3.2 Bypasses 6-12
6.4 Plugs and capillary filaments 6-13
6.4.1 Plugs moved by capillary filaments 6-14
6.4.2 Plugs blocked by reverse capillary filaments 6-14
Conclusions 6-14
References 6-16
7 Applications 7-1
7.1 Materials and fabrication 7-1
7.2 Space: design of vanes 7-3
7.2.1 Space cup 7-3
7.2.2 Vanes 7-3
7.3 Microfluidics 7-4
7.3.1 Capillary channels on paper 7-4
7.3.2 Evaporation capillary pumping 7-5
7.4 Biology, biotechnology and medicine 7-6
ix