Preface	6
	Contents	9
	About the Editors	11
	1 A Historical Perspective on Paper Microfluidic Based Point-of-Care Diagnostics	14
	Abstract	14
	1.1 Introduction	14
	1.2 Paper Microfluidics: Historical Perspective	15
	1.3 Outline	16
	References	17
	2 Fluid Transport Mechanisms in Paper-Based Microfluidic Devices	19
	Abstract	19
	2.1 Introduction	20
	2.2 Fluid Transport	23
	2.2.1 Classical Lucas-Washburn Equation (Capillary Flow)	24
	2.2.2 Darcy’s Law for Fluid Flow	26
	2.2.3 Fluid Transport in the Porous Media of Varying Cross Section/Arbitrary Shape	27
	2.2.4 Radial Fluid Transport in Porous Media	30
	2.2.5 Diffusion-Based Fluid Transport	31
	2.2.6 Lateral Flow Immunoassay (LFIA)	32
	2.3 Summary	38
	References	38
	3 Fabrication Techniques for Paper-Based Microfluidic Devices	41
	Abstract	41
	3.1 Introduction	41
	3.2 Fabrication Methods	43
	3.2.1 2D Fabrication Methods	43
	3.2.2 Flexographic Printing	45
	3.2.3 3D Fabrication Methods	53
	3.3 Comparison of Various Fabrication Methods	56
	References	56
	4 Flow Control in Paper-Based Microfluidic Devices	58
	Abstract	58
	4.1 Introduction	58
	4.2 Fluid Flow Through Porous Substrates	59
	4.2.1 Lucas-Washburn Equation	59
	4.2.2 Darcy’s Equation for Fluid Flow	60
	4.2.3 Richard’s Equation for Partially Saturated Flows	60
	4.3 Controlling the Fluid Flow in Paperfluidic Devices	61
	4.3.1 Techniques to Achieve Flow Control Without Valves	62
	4.3.1.1 Changing the Channel Dimensions	62
	4.3.1.2 Creation of Alternate Flow Paths	62
	4.3.1.3 Changing the Surface Wettability	63
	4.3.1.4 Changing the Properties of the Porous Substrate	65
	4.3.1.5 Increasing the Resistance to Fluid Flow Using Physicochemical Barriers	65
	4.3.1.6 Electrostatic Interactions Between Device Components	66
	4.3.1.7 Varying the Channel Dimensions for Specific Introduction of Reagents	67
	4.3.2 Techniques to Achieve Flow Control Utilizing Valve-Like Tools	68
	4.3.2.1 Dissolvable Species	68
	4.3.2.2 Mechanical Tools Which Connect or Disconnect Channels	69
	4.3.2.3 Wax-Based Valves	71
	4.3.2.4 Fluidic Diodes	72
	4.3.2.5 Automatically Actuated External Valves	73
	4.4 Challenges to Translation of Flow Control-Based Paperfluidic Devices	74
	References	75
	5 Paper Microfluidic Based Device for Blood/Plasma Separation	78
	Abstract	78
	5.1 Introduction	79
	5.2 Physiological Hemodynamics and Porous Media Hemodynamics	81
	5.3 Recent Advances in Paper Based Blood Plasma Separation Devices	82
	5.4 Summary and Future Perspectives	89
	References	90
	6 Evolution of Paper Microfluidics as an Alternate Diagnostic Platform	93
	Abstract	93
	6.1 Introduction	94
	6.2 Point-of-Care (POC) Diagnostics	95
	6.3 Fabrication of Paper-Based Devices	96
	6.4 Diagnostic Assays	99
	6.4.1 Chemical-Based Assays	100
	6.4.2 Immunoassays	101
	6.4.3 DNA Hybridization on Paper	102
	6.5 Blood Plasma Separation	103
	6.6 Limitations of the Assays	104
	6.7 Three-Dimensional (3D) Paper Devices	105
	6.8 Conclusions and Outlook	106
	References	106
	7 Paper-Based Microfluidic Devices for the Detection of DNA	109
	Abstract	109
	7.1 Introduction	109
	7.2 Evolution of Paper-Based Devices	111
	7.3 Principle of Detection/Reaction Mechanism	112
	7.4 Fabrication Schemes of Microfluidic Paper-Based Devices	113
	7.4.1 Wax Printing	113
	7.4.2 Photolithography	115
	7.4.3 Inkjet Printing	115
	7.4.4 Laser Treatment	115
	7.4.5 Plasma Treatment	116
	7.4.6 Wet Etching	116
	7.5 Applications of ?PADs in DNA Sensing	118
	7.6 Conclusions	119
	References	121
	8 Nucleic Acid Amplification on Paper Substrates	124
	Abstract	124
	8.1 Introduction	124
	8.2 Nucleic Acid Extraction	126
	8.3 Nucleic Acid Amplification	128
	8.3.1 Loop-Mediated Isothermal Amplification (LAMP)	129
	8.3.2 Helicase-Dependent Amplification (HDA)	134
	8.3.3 Recombinase Polymerase Amplification (RPA)	137
	8.3.4 Rolling Circle Amplification (RCA)	139
	8.3.5 Strand Displacement Amplification (SDA)	140
	8.4 Detection of the Amplified DNA	142
	8.4.1 Colorimetric Detection	142
	8.4.2 Fluorescence Detection	143
	8.5 Factors Affecting the Efficiency of DNA Amplification on Paper	144
	8.5.1 Choice of the Amplification Technique	145
	8.5.2 Choice of the Paper Substrate	149
	8.5.3 Role of Reagent Storage, Transport and Rehydration	150
	8.6 Conclusion	151
	References	152
	9 Paper-Based Devices for Food Quality Control	156
	Abstract	156
	9.1 Introduction	157
	9.2 Paper-Based Sensors in Microfluidics	158
	9.3 Fabrication Techniques	160
	9.3.1 Two-Dimensional Cutting	162
	9.3.2 Wax Patterning	162
	9.3.3 Flexographic Printing	162
	9.3.4 Alkyl Ketene Dimer (AKD) Printing	163
	9.3.5 Three-Dimensional (3D) Paper-Based Microfluidics	163
	9.3.6 Additional Functional Elements	163
	9.4 Applications to Food Quality Testing	165
	9.4.1 Control of Food Adulteration	165
	9.4.2 Pathogen Detection in Food	166
	9.4.3 Pesticides and Herbicides Detection in Food	167
	9.4.4 Heavy Metals in Food	167
	9.5 Summary	167
	References	168
	10 Paper Based Sensors for Environmental Monitoring	173
	Abstract	173
	10.1 Introduction	173
	10.2 Development of Paper Based Sensor	176
	10.3 Detection Techniques	177
	10.3.1 Calorimetry Detection	177
	10.3.2 Surface-Enhanced Raman Spectroscopy (SERS) Based Detection	178
	10.3.3 Electrochemical Detection	179
	10.3.4 Luminescence Based Detection	180
	10.4 Paper Based Sensors for Environmental Monitoring	181
	10.4.1 Paper Based Sensor for Water Quality Monitoring	181
	10.4.2 Paper Based Sensor for Air Quality Monitoring	184
	10.5 Challenges	185
	10.6 Conclusion	186
	References	187
	11 Paper-Based Energy Storage Devices	190
	Abstract	190
	11.1 Introduction	190
	11.2 Fabrication Methods	192
	11.2.1 Printing	192
	11.2.2 Pencil Drawing	194
	11.2.3 Chemical and Physical Deposition	196
	11.2.4 Vacuum Filtration and Dip Coating	197
	11.3 Conclusion	197
	References	198
	12 Paper-Based Devices for Wearable Diagnostic Applications	199
	Abstract	199
	12.1 Introduction	199
	12.2 Fabrication Techniques of Microfluidic Paper-Based Analytical Devices	200
	12.2.1 Photolithography	200
	12.2.2 Inkjet Printing	201
	12.2.3 Laser Cutting	202
	12.2.4 Wax Printing	203
	12.2.5 Polydimethyl-Siloxane (PDMS) Printing	203
	12.3 Detection Techniques	203
	12.3.1 Colorimetric Detection	203
	12.3.2 Electrochemical Detection	205
	12.3.3 Chemiluminescence Detection	205
	12.3.4 Fluorescence	206
	12.3.5 Electrochemiluminescence	206
	12.4 Applications	207
	12.5 Challenges and Future of Microfluidic Paper-Based Analytical Devices	210
	12.6 Summary	212
	References	213
	13 Paper Microfluidic-Based Devices for Infectious Disease Diagnostics	215
	Abstract	215
	13.1 Introduction	215
	13.2 Pathogen Detection	216
	13.2.1 Escherichia Coli	216
	13.2.2 Plasmodium	217
	13.2.3 HIV	218
	13.2.4 HBV	219
	13.2.5 ZIKA Virus	220
	13.3 Health Diagnostics	220
	13.4 Commercialization and Challenges	226
	13.5 Conclusion and Future Perspectives	228
	References	230