Technologies for Smart Sensors and Sensor Fusion

2	Tailoring Wettability for Passive Fluid Control in Microfluidics

Craig Priest

CONTENTS

2.1    Introduction

2.2    Theory of Wetting

2.2.1    Thermodynamic Equilibrium

2.2.2    Wetting Hysteresis

2.2.2.1    Advancing and Receding Contact Angles

2.2.2.2    Quantifying Hysteresis Behavior

2.2.3    Dynamic Wetting

2.3    Tailoring Microchannel Wettability

2.4    Fluid Control in Microchannels

2.4.1    Capillary Flow

2.4.2    Capillary (Laplace) Valves

2.4.3    Wettability Flow Guides

2.4.4    Dispersed Phase Microfluidics

2.5    Summary and Outlook

Acknowledgments

References

2.1  INTRODUCTION

Interactions of solid surfaces with droplets, streams, and films of liquid occur in a wide variety of natural processes and are exploited in countless ...