Open-Channel Microfluidics: Fundamentals and Applications

Open microfluidics, the study of microflows having a boundary with surrounding air, encompasses different aspects such as paper or thread-based microfluidics, droplet microfluidics and open-channel microfluidics.

Open-channel microflow is a flow at the micro-scale, guided by solid structures, and having at least a free boundary (with air or vapor) other than the advancing meniscus. This book is devoted to the study of open-channel microfluidics which (contrary to paper or thread or droplet microfluidics) is still very sparsely documented, but bears many new applications in biology, biotechnology, medicine, material and space sciences. Capillarity being the principal force triggering an open microflow, the principles of capillarity are first recalled. The onset of open-channel microflow is next analyzed and the fundamental notion of generalized Cassie angle (the apparent contact angle which accounts for the presence of air) is presented. The theory of the dynamics of open-channel microflows is then developed, using the notion of averaged friction length which accounts for the presence of air along the boundaries of the flow domain. Different channel morphologies are studied and geometrical features such as valves and capillary pumps are examined. An introduction to two-phase open-channel microflows is also presented showing that immiscible plugs can be transported by an open-channel flow. Finally, a selection of interesting applications in the domains of space, materials, medicine and biology is presented, showing the potentialities of open-channel microfluidics.

Jean Berthier received an MS in Mathematics from the University of Grenoble, an engineering diploma from the Institut National Polytechnique in Grenoble, and a PhD from the University Pierre et Marie Curie in Paris. After spending four years at Sandia and Los Alamos National laboratories, he joined the CEA-Leti in Grenoble, France. In 2018 he joined the University of Washington in Seattle. He is the author of the books Microfluidics for Biotechnology, Microdrops and Digital Microfluidics, The physics of Micro-droplets, and Open Microfluidics.

Ashleigh Theberge is an Assistant Professor of Chemistry at the University of Washington and Adjunct Assistant Professor of Urology at the University of Washington School of Medicine. She received a BA in Chemistry from Williams College and a PhD in Chemistry from the University of Cambridge. She completed her postdoctoral fellowship in Biomedical Engineering, Toxicology, and Urology at the University of Wisconsin-Madison. She joined the faculty at the University of Washington in 2016, where she leads the Bioanalytical Chemistry for Medicine and the Environment group.

Erwin Berthier is a cofounder and CTO of Tasso Inc. a Seattle-based company developing patient-centric, distributed, health technologies. He received a Diplome D'Ingenieur in Fluid Mechanics from ENSTA (Ecole Nationale Superieure des Technologies Avancees) in Paris, a Masters of Electrical Engineering from the University of Canterbury (New Zealand), and a PhD in Biomedical Engineering from the University of Wisconsin in Madison. He is also a co-author of the book Open Microfluidics. Erwin currently works in the Department of Chemistry at the University of Washington.