Advanced Microfluidics (lecture)

 

Objectives

After participation in this course, the student is able to:

1. compare various active and passive microfluidic techniques by highlighting their differences

2. describe the major principles of internal and external forces employed in microfluidic platforms

3. analyze various microfluidic fabrication techniques for microparticle manufacturing

4. design and simulate basic microfluidics systems by applying the knowledge acquired during the course

Description

The course will start by briefly introducing the field of microfluidics and its importance in diagnostics, pharmaceutical, medicine, etc. We will succinctly discuss the benefits of going smaller (microscale) by highlighting the difference between laminar and turbulent flows. Important concepts in microfluidics, such as scaling laws, Brownian motion, capillary flow, flow resistance, pumping mechanisms, diffusive mixing, pressure drops, flow rates and velocities, channel designs and dimensions, interfacial tensions and instabilities, etc., will be revised briefly for the better understanding of subsequent topics. It is recommended but not compulsory to take the “BioMEMS and Microfluidics” course by Prof. Bernhard Wolfrum, where the above introductory topics are covered in detail. We will distinguish between the active (acoustofluidics, dielectrophoresis, magnetophoresis, optofluidics, etc.) and passive (hydrodynamics, inertial microfluidics, gravitational, pinch flow fractionation, etc.) microfluidic systems, and list their advantages and disadvantages. We will then proceed to discuss in detail major microfluidic techniques used to manipulate cells, particles, droplets, microorganisms, and fluids. We will learn how a combination of more than one technique, e.g., dielectrophoretic and gravitational forces, or pinched flow fractionation and optical forces, can be combined to realize a hybrid microfluidic system. Moreover, we will learn the mechanism of microfluidic droplet generation, single cell/molecule encapsulation and limitations imposed by Poison statistics. We will also discuss paper microfluidics, digital microfluidics, and microfluidics-based particle fabrication using continuous/stop flow lithography techniques. Moving along, we will discuss various applications, such as mixing, sorting, separation, concentration, patterning, encapsulation, etc., of these techniques mentioned above. Alongside, we will learn to design microfluidic devices and simulate microfluidic flows using COMSOL Multiphysics.

Course topics:

• Introduction to microfluidics

• Important concepts in microfluidics

• Active and passive microfluidics

• Hybrid microfluidic systems

• Droplet microfluidics

• Digital microfluidics

• Paper microfluidics

• Centrifugal microfluidics

• Microfluidic manufacturing

• Applications of microfluidics

Teaching and learning methods

The module will comprise lectures (2SWS) and exercises (2SWS). The lectures will introduce the students to a range of microfluidic concepts and techniques, from very basic to very advanced. The course will provide an overview of the field of microfluidics to the students and would help them incorporate some of the acquired knowledge in their research projects in the future. During the exercise, the students will discuss and design microfluidics systems and simulate them. This will help the students to achieve a deeper understanding of the topics, and to apply the taught concepts to practical tasks. The students (in groups of 2-3) will chose a topic of their own interest, and simulate a microfluidic flow problem and analyze the results. At the end, the students group will present their results in a project presentation. In combination, this will help the students to acquire the teaching goals, which are listed above.

Presence: 60 hrs, Self study: 90 hrs, Total workload: 150 hrs

Media

PowerPoint presentations will be used during the lectures, and made available via Moodle after each lecture. During the exercise, tutorials on the design and simulation of microfluidic systems will be given, and the relevant files will be shared via Moodle after the exercise.

Literature

[1] A. Menz, Microfluidics and Lab-On-A-Chip (Royal Society of Chemistry, 2020).

[2] H. Bruus, Theoretical Microfluidics (Oxford Master Series in Physics, 2007).

[3] B. J. Kirby, Micro- and Nanoscale Fluid Mechanics, 1st ed. (Cambridge University Press, New York, 2013).

Examination

Written exams: 40% (midterm 1) + 40% (midterm 2); Project presentation: 20%

In the written exam, the students demonstrate their knowledge of microfluidics and associated physical phenomenon by answering questions with limited supporting material. They will also show their ability to transfer the conveyed concepts through their project presentation.