DROPLET MICROFLUIDICS
Charles Baroud, Institut Pasteur, France
Håkan Jönsson, KTH Royal Institute of Technology, Sweden
Yegan Erdem, Bilkent University, Ankara, Turkey

Workshop Description:
Droplet microfluidics has emerged from being the playground of physicists to becoming one of the most widely deployed platforms. This wide adoption of droplet techniques has taken place, despite the complexity of flows and chemistry of droplets, because droplets solve many of the difficulties of single-phase flows such as mixing, transport, fluid manipulation, etc. When considering the use of droplet methods, it is therefore useful to understand some of the basics of multiphase flow, and to become familiar with the methods that have been devised to produce, transport, merge, and otherwise manipulate droplets.

In this workshop we will present the fundamental physics of multiphase flows, both within microchannels and on solid surfaces. These fundamental aspects will then be followed by a lecture on the engineering of droplet microfluidic devices and their applications for different fields of biological questions.

Overview of Material to Be Covered and What Attendees Can Expect to Take Away From the Workshop:
This workshop part contains 3 lectures:

1. The first lecture begins by presenting the fundamentals of multiphase flows, including the concept of surface tension, contact angle, and Laplace pressure jump. These physical ingredients are then used to explain some of the basic properties of droplet-based flows, including the physics of droplet breakup, the recirculation flows in moving droplets, and the pressure imbalance that leads to droplet merging. Finally, we will study how 3D microchannel geometries can be used to produce, direct, or hold droplets.
2. The second lecture focuses on the droplet microfluidics toolset and its uses, benefits and limitations in bioanalytical applications. Fundamental as well as more novel droplet processing operations will be covered. The main focus of the lecture will be droplet microfluidic applications, constructed from the fundamental droplet processing operations, for example ddPCR, DNA/RNA processing, droplet barcoded sequencing, as well as single cell high throughput screening and tissue engineering. Finally, automation, interfacing and scaling of droplet systems will be discussed.
3. In the third lecture of the workshop the physical factors that affect wetting of surfaces will be discussed and major focus will be on droplet manipulation techniques on surfaces. Surface based droplet manipulation methods such as electrowetting, Marangoni forces and textured surfaces will be discussed along with examples from literature.

Who Should Attend:
The workshop will present a broad overview of droplet methods. As such it is intended primarily at early practitioners of droplet microfluidics or those wishing to get an introduction to the subject. It can also serve to give a foundation to biologists or chemists who use droplet microfluidics and would like to understand the underlying physics and engineering aspects. We will be happy to go into more detailed issues during the discussion session on Oct. 4th.

Participants Will Need the Following:
No special requirements.