GOALS:
To explore the world of microelectromechanical devices and systems ("MEMS"). This requires an awareness of material properties, fabrication technologies, basic structural mechanics, sensing and actuation principles, circuit and system issues, packaging, calibration, and test. We will cover this through a combination of lectures, case studies, individual homework assignments, and design projects carried out in teams.
CLASSES: Lectures, Wednesday and Friday, 11 AM-12:30 PM, Room 56-154. Additional hour to be scheduled for each team project.
CREDIT: Grad H credit, 4-0-8
REQUIRED WORK: The plan is for seven individual homework assignments, usually requiring some independent work either in the library or with modeling, plus a final design project done in teams of four or five students. A preliminary short report on the design project is due in early April; a brief intermediate report is due at the end of April, and the final design project presentations will occur during the last class or two, depending on the number of projects.
GRADES: Approximately 50% on homework; 50% on the final project. It is hoped that everyone will get a grade of A.
POLICY ON COOPERATION: Students learn best from each other. There is no restriction on cooperation, discussions, use of texts, library materials, or other sources while learning how to do any assignment. In fact, we will set up an e-mail alias for sharing comments on each assignment. If a solution to a problem is found in the literature, students are expected to provide correct citations to that literature. But for the individual homework assignments, every student is expected, at the end, to have worked through their own analysis or modeling work, and to have written up their own work for submission. Under no circumstances is it permitted to present another student's work as one's own. For the term projects, a single report from each team is to be prepared. Cooperation in this case is an essential part of the assignment.
Ms. Tracy Gabridge, the librarian responsible for EECS, will conduct a library orientation specifically for 6.777J/2.751J on FRIDAY, FEBRUARY 13 in Room 14N-132. There will be two sessions: 1:30-3 PM and 3-4:30 PM. Going to any one session is fine.
She will demonstrate how to use the on-line search engines of the MIT Libraries to find sources. She also maintains the 6.777J/2.751J Library Web Site, with all kinds of useful links selected for this course. Knowing how to use a library is an essential skill. If you do not have good library search skills, it is strongly recommended that you attend.
The number of lectures on each topic are given in parentheses.
I. Introduction (1) An overview of microelectromechanical devices and technologies, and an introduction to design and modeling.
II. Fabrication Technology (2) Brief review of standard microelectronic fabrication technologies; detailed discussion of bulk micromachining, surface micromachining, bonding technologies, and related fabrication methods. Assignments will emphasize the relation between process and mask specifications and the resulting device geometry, and also the effect of etch selectivity on process viability.
III. Material Properties (1) Definitions of mechanical, thermal, electrical, magnetic, optical, and chemical properties of materials. A library assignment to locate information on material properties accompanies this unit.
IV. Lumped Modeling (3) Introduction to lumped modeling of systems and transducers; an overview of system dynamics.
V. Mechanics (3) Elasticity, structures, and energy methods.
VI. Dissipation (2) The thermal energy domain; modeling dissipative processes.
VII. Fluids and Transport (3) A necessarily brief introduction to the fluid mechanics and transport processes relevant at the microscale.
VIII. System Issues (3) Electronics, feedback, and noise.
IX. Case Studies & Special Topics (8) While students are working on final projects, a series of eight lectures covering packaging, nanotechnology, as well as case studies taken from various MEMS disciplines (e.g., pressure sensors, accelerometers, BioMEMS).
DESIGN PROJECTS:
Some sample design projects used in previous terms are described briefly below, and are representative of the types of projects we will use. Descriptions, specifications and design goals for this term's projects will be provided later in the term. The scope of each project will include a microfabricated device, the drive/detection electronics, and a packaging concept. Each project will have a team of four or five students. Depending on enrollment, there may be more than one team on a given topic.
1. A fast dielectrophoretic cell sorter
Cell sorting is a commonly used biological technique that can isolate target
cells from a bulk population based on differences in size, shape, or molecular
specificity. In this project you will explore the fundamental limits for micro-flow
sorters by designing a truly fast (>1,000 cells/sec) micro-cell sorter. The
sorter will be created out of PDMS on glass and will use dielectrophoresis to
push incoming cells into one of two outlet microchannels. In the process you
will couple it to an optically based detection system, actuation electronics,
and identify the fundamental limits on sorting.
2. A piezoresistive sensor for biomolecular recognition
The goal of this project is to create cantilever-based device that detects stress
induced by molecular binding. Two cantilevers (operated differentially) will
be created out of SU-8 with integrated poly-Si piezoresistors. The packaged
device will be used in a hand-held point-of-care diagnostic monitor and so must
be robust, small, and connected to a circuit that gives an output proportional
to the logarithm of the concentration ratio.
3. RF-IF filter
The superheterodyne radio receiver, one of the truly brilliant inventions of
the 20th century, uses a nonlinear frequency converter in combination with a
tunable local oscillator to convert the incoming radio signal to a lower fixed
frequency (the so-called “intermediate frequency” or “if”).
The goal of this project is to design a surface-micromachined silicon resonator
or combination of resonators that are used to create an if filter for incorporation
into a one-chip radio.
4. A micro flex-tester for measuring the compliance of microstructures
The goal of this project is to build a microfabricated force-displacement sensor
device to characterize the compliance of microstructures. The micro-flextester
is a metrology tool used to measure the actual force-displacement characteristic
of microfabricated compliant structures. You will select a sensing scheme (i.e.,
piezoresistive strain gauges or capacitive displacement sensors) and use it
in a device that must be small, have tunable force resolution, and integrated
displacement and force sensing.
TEXTS AND REFERENCE MATERIALS:
REQUIRED: Stephen D. Senturia, Microsystem Design, Kluwer, 2001.
SUPPLEMENTARY READING:
Books and Monographs:
Marc Madou, Fundamentals of Microfabrication, CRC, 1998 & 2002.
Gregory T.A. Kovacs, Micromachined Transducers Sourcebook, McGraw-Hill, 1998.
Nadim Maluf, An Introduction to Microelectromechanical Systems Engineering, Artech House, 2000.
A. Nathan and H. Baltes, Microtransducer CAD: Physical and Computational Aspects,, Springer, 1999.
B. Romanowicz, Methodology for the Modeling and Simulation of Microsystems, Kluwer, 1998.
Masood Tabib-Azar, Microactuators, Kluwer, 1998.
Julian W. Gardner, Microsensors: Principles and Applications, Wiley, 1994
Ljubisa Ristic, Editor, Sensor Technology and Devices, Artech House, 1994
D. S. Ballantine, et. al., Acoustic Wave Sensors, Academic Press, 1997
H. J. De Los Santos, Introduction to Microelectromechanical (MEM) Microwave Systems, Artech, 1999.
James M.Gere and Stephen P. Timoshenko, Mechanics of Materials, 2nd Edition, Brooks/Cole Engineering Division, 1984. Stephen A. Campbell, The Science and Engineering of Microelectronic Fabrication, 2nd Edition, Oxford, 2001
IEEE Reprint Books:
R. S. Muller, et. al., Editors, Microsensors, IEEE Press, 1991
W. Trimmer, Editor, Micromechanics and MEMS, IEEE Press, 1997
Journals:
J. Microelectromechanical Systems (IEEE/ASME)
Sensors and Actuators (Elsevier)
Sensors and Materials (MYU, Japan -- in English)
J. Micromechanics and Microengineering (IOP)
Major Conference Proceedings:
Transducers 'XX (International Conference on Solid-State Sensors and Actuators), odd-numbered years since 1983, proceedings available from IEEE (US Meetings), Elsevier (European Meetings), IEE Japan (Japanese Meetings).
MEMS 'XX (IEEE Workshop on Micro Electro Mechanical Systems), annual since 1989.
Eurosensors 'XX, annual since 1987, proceedings published in special issues of Sensors and Actuators.
Solid-State Sensors and Actuators Workshop, Hilton Head, SC, even-numbered years since 1984, proceedings available from Transducer Research Foundation.
Japanese Sensor Symposium, annual since 1982; technical digest published in English by the Institute of Electrical Engineers of Japan (IEE)