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prepared by C.-f. Chen

Last updated: 11/14/2018

Title:ME 640, Microfluidics, 3 credits (contact hours: 3)

Time/Place 3 hours per week (either by MWF 1-hr or T/TR 1.5 hr).

Instructor Dr. Cheng-fu Chen

Assistant Professor

Department of Mechanical Engineering

Duckering 349D

(907) 474-7265

Office hours2 hours per week (TBD) or by appointment

Prerequisites.PHYS 211X (for engineering, math and physics major) or PHYS 103X (for math and non-physics science major); ES341 OR instructor approval;graduate standing.

All classroom behavior should be strictly compliant to the UAF’s Honor Code.

"Students will not collaborate on any quizzes, in-class exams, or take-home exams that will contribute to their grade in a course, unless permission is granted by the instructor of the course. Only those materials permitted by the instructor may be used to assist in quizzes and examinations.

Students will not represent the work of others as their own. A student will attribute the source of information not original with himself or herself (direct quotes or paraphrases) in compositions, theses and other reports.

No work submitted for one course may be submitted for credit in another course without the explicit approval of both instructors.

Violations of the Honor Code will result in a failing grade for the assignment and, ordinarily, for the course in which the violation occurred. Moreover, violation of the Honor Code may result in suspension or expulsion."

Course Readings / Materials

Textbook: None. (Instructor’s notes)

References (recommended, all the books are available and reserved at the Rasmuson Library):

  1. Theoretical Microfluidics, by Henrik Bruus, OxfordUniversity Press, (ISBN 978–0–19–923508–7), 2008.
  2. Fundamentals and Applications of Microfluidics, by Nam-Trung Nguyen and Steven T. Wereley, Artech House, 2nd ed, 2006.
  3. Microsystem Engineering of Lab-on-a-chip Devices, Oliver Geschke (Editor), Henning Klank (Editor), Pieter Telleman (Editor), Wiley, 2004. (I have a copy of some chapters of this book.)
  4. Introduction to Microfluidics, by P. Tabeling (translated by S. Chen), Cambridge University Press, 2006.
  5. M. J. Madou, Fundamentals of microfabrication, the science of miniaturization, CRC Press, 2nd Ed., 2001.
  6. Assigned papers.

Reference Journals: Lab on a Chip (in contact with library to order this journal. Before it is available, the instructor will provide copies of papers he had.)

Course Description

This course is aimed at promotingstudents’ learning interest in the fundamental concepts and principles and of fluids at the micron (and/or sub-micron) scales. With the basic understanding of the fundamental physical laws in hand, the course will also introduce the up-to-date microfluidic technology in modeling, simulation, design, and fabrication of microfluidic devices. Discussions will be placed in their applications to engineering and bioengineering.

The course constitutes three parts. The first part is on the physics of fluids (and droplets) at the micron scale to prepare students the needed knowledge of understanding how microfluidics works and how microfluidic devices are designed using the physical significance of the fluids at the small scale. The second part is on the introduction of microfluidic devices—micro- pumps, valves, mixers, sorters—and their design principles and fabrication processes including the silicon-based photolithography and polymer-based sift lithography. The last part focuses on the (bio) engineering applications. Since this course is to prepare students to further explore the microfluidics topics, the course subjects to be covered will also broadly include contemporary relevant topics such that each student may be exposed to the topic(s) of their own interests.

This class will be using Blackboard as an aid to communication.

Catalog Description:

Overview of basic concepts and principles of fluids at the micron scale; introduction to the design and fabrication of microfluidic devices; discussions of design, fabrication, and applications of microfluidic devices.

Course Goals.

Overview the principles of microfluidics and introduce the design and fabrication of microfluidic devices (pumps, valves, mixing devices, sorting devices, etc) and their applications (mixing, sorting, metering, etc.) in the fields of engineering and bioengineering.

Student Learning Outcomes

Students will learn from this class about the fluid behaviors at the small scale. The knowledge gained will first complement students’ leaning from ES 341 Mechanics of Fluids, and then learn the contemporary research and technologies in micro-fabrications. Students will be poised to advanced, independent study and research of microfluidics in the related research fields.

Instructional Methods.

Lectures.

Course Policy

Students will be evaluated on the base of their turn-in assignments and exams.

All written work must be presented on its due date at the beginning of class. Failure to submit homework in time will result in a total loss of the credit. Studentsare required to finish all the homework problems.

Two 2-hour exams and one final examination will be held. Exam problems may come from, but not limited to, the materials in homework assignments, lecture presentations, and/or handouts. Exams must be taken when given. Make-up exam accommodation will be provided only for the leave of intercollegiate sports, jury duties, and (short-term) medical leave; show the instructor any supportive documents for acquiring a make-up exam.

If you are to take a makeup exam, we expect that you have no substantial knowledge of the content of the original exam. If you have found out about the exam content, you are obligated to tell this to your professor well before the scheduled time of the makeup exam.

Appropriate Class Behavior. Arrive on time or be prepared to be asked to leave, remain in the classroom during class time (wandering not allowed), stay alert, and participate actively. If you choose not to attend class you are on your own for taking exams. You cannot make up in-class work. You are welcome to bring a drink or snack to class, as long as you clean up after yourself and.

Student Assignments

There are 8~10 homework assignments for students to conduct calculations and simulations of the problems assigned. Each such homework is due one week after the assignment is given.

Each student needs to conduct a term project by choosing a topic assigned or approved by the instructor. Graduate students are encouraged to team with an undergraduate for the term project. In addition, the instructor has some limited materials for prototyping. Contact the instructor if you have intention to prototype some microfluidic devices. The instructor probably is able to afford materials for one team. The instructor will periodically provide students reading materials; students are also highly suggested to conduct independent research on the topic. Each student must keep a weekly update (10-min oral presentation) in class about their progress on the term project.

In the last week of instruction, (each group of) students need to conduct a 30-minute in-class presentation of their term project. Your project will be evaluated by the following criteria:

  • The degree of challenge of the topic.
  • Technical rigors.
  • Communications (paper writing & oral presentation).

Exam. Two exams will be held in the semester.

GradingThe performance of each student will be evaluated by:

Homework assignment / 30%
2 exams / 25% each
Term project / 20%
Total / 100%

Final course grades will be determined by:

A+ / > 95.1 / B- / 74-78.9
A / 90-95 / C+ / 70-73.9
A- / 87-89.9 / C / 65-69.9
B+ / 82-86.9 / C- / 61-64.9
B / 78-81.9 / D / 60-60.9
F / <60

Disabilities Services

Reasonable accommodation will be provided for students with disabilities, who may wish to contact the Office of Disability Services (Phone # 474-7043, TTY 474-7045) for further assistance.

Support Services

Student Support Services

Computing Services

ARSC consultant 450-8602 (If you desire to perform numerical simulations using COMSOL, please contact the instructor as soon as possible. You will need to open an account through the ARSC consultant and it will take about 1~2 weeks.)

Course Outline (in progress, subject to change)

Week / Content
1 /
  • What is microfluids? The motivation.
  • Introduction
  • Review of photolithograph, and some pictures
  • A feeling about the length scales
  • Continuum assumptions
Reading Assignment 1
  1. read the handouts of photolithography, length scale, continuum assumptions
  2. read the online information (listed on the homework sheet) about the definition and introduction of microfluidics
  3. read the handout writing guide reference
  4. write a 1-page, 3 paragraph essay summarizing your reading.

2 / Review of fluid mechanics, with an endeavor toward microfluidics
  • Introduction to microfluidics
  • Review of fluid mechanics – week 2 reading
  • slides for review of fluid mechanics
Reading Assignment 2 and Calculation Assignment 1
  • This assignment will help shorten the gap between the conventional fluid mechanics and microfluidics by reviewing and self-studying some basic flow problems such as the Stokes flow, laminar flow, Couette flow, and Poiseuille flow.

3 / Random walk and porous media.
  • Basic probability and random walk principle
  • Equivalent modeling of porous media (by the diffusion-to-capture models)

4 / Diffusion kinematics (stochastic-based vs. continuum-based modeling)
  • Diffusion – microscopic theory vs. macroscopic theory
Calculation Assignment 2
  • This assignment will be on the exercise of the random walk principle.

5 / Dispersion (combined diffusion and dispersion)
  • Taylor dispersion model
  • Applications to microfluid flow mixing and particle separation

6 / Stokes flow (low Reynolds number flow)
  • governing equation
  • drag coefficient and frictional force; Einstein’s equation
  • sedimentation speed
Reading Assignment 3
  • Read the papers written by Taylor (1953, 1954) and by Bello (1993) about the original work and one application of Taylor dispersion.
  • Exercise on calculating the effective coefficient of porous-medium diffusion.

7 / Surface tension, droplets, and capillary force
  • review of differential geometry and Young’s equation
  • droplets in asymmetric microchannels
Reading Assignment 4
  • survey and review the existing techniques for measuring the diffusion coefficients in bulk fluids and in fluids filled with pores or diffusion obstacles.

8 / Surface tension, droplets, and capillary force
  • capillary force
  • applications (water strider, self organization, coating)
Reading Assignment 5
  • Read and summarize the handout papers regarding sedimentation of particles in polymers.

9 / Microfluid flow-driven principles
  • electro-osmosis
  • electrophoresis
  • electrokinetics

10 / Review and design of microfluidic devices
  • pumps
  • valves
  • metering
Reading Assignment 6 and determine the topic for your term project
  • review the handouts about the driving principles of microfluidics and write a 2-page essay summarizing your reading (and findings).
  • find or consult the instructor for a topic you would like to do as your term project (you may team with a undergradate).

11 / Review and design of microfluidic devices
  • mixing (Taylor dispersion, droplet forming + frictional rotation)
  • sorting
  • a sorting device - Brownian ratchet

12 / Micro-fabrication
  • silicon-based (MEMS, photolithography)
  • polymer-based (soft lithography)
Reading Assignment 7
  • If you are teamed to conduct a term project, please outline your term project in a 1 page, 5 paragraph essay format. (what the topic is, why it is important, how it works, physical significance, conclusions). Otherwise, read the handout about mixing and separation at the micro scale and summarize your reading in a 2 page essay.

13 / Prototyping microfluidic channels, devices, systems.
  • micro-molding
  • shrink dink
  • review of some well-know prototypes (Stanford’s pneumatic control channels, droplet-forming devices, …)

14 / Applications of Microfluidics
  • lab on a chip
  • jet-spray printer
  • sorting particles
  • mixing fluids
  • micro reactors
  • explanation of water transport in plants and trees
  • mics (TBD)

15 / Project presentations
Term paper due