This document discusses micro and smart systems, including MEMS (Micro Electro Mechanical Systems). It provides an overview of the course, including the lecture modules and coordinators. MEMS combine microelectronics and micro-mechanics and sometimes micro-optics. They allow for miniaturization through batch processing and integration of mechanical and electronic components. Examples of MEMS include sensors, actuators, and microstructures. The document also provides examples of applications that require miniaturization, such as biomedical devices, aerospace systems, and lab-on-a-chip technologies.

1. Prof.K.N.Bhat, IISc Bangalore 1
Micro and Smart Systems
1. G.K. Ananthasuresh , Mechanical Engineering ,IISc
IIScsuresh@mecheng.iisc.ernet.in
2. K.J. Vinoy, Electrical Communications Engineering, IISc,
kjvinoy@ece.iisc.ernet.in
3. S. Gopalakrishnan, Aerospace Engineering, IISc ,
Krishnan@aero.iisc.ernet.in
4. K.N. Bhat, Electrical Communications Engineering, IISc.
knbhat@gmail.com
Course coordinators

2. Prof.K.N.Bhat, IISc Bangalore 2
Module 1: Introduction - Lectures 1 to 6
Module 2: Microfabrication processes –Lectures 7 to 14
Module 3: Mechanics of Solids - Lectures 15-24
Module 4: Finite element method – Lectures 25 to 30
Module 5: Electronics and packaging - Lectures 31 to 40
Lecture Modules

3. Prof.K.N.Bhat, IISc Bangalore 3
1) S.D. Senturia, Microsustem Design, Kluwer
Academic Publishers, 2001
2) Tai-Ran Hsu, MEMS & Microsystems Design and
Manufacture, McGraw Hill, 2002
3) V.K. Varadan, K.J. Vinoy, and S. Gopalakrishnan,
Smart Material Systems and MEMS: Design and
Development Methodologies, Wiley, 2006
Text / References
Suggested hyperlinks
http://www.memsnet.org/mems,
/http://www.analog.com/en/mems-and-
sensors/products/index.html
http://web.mit.edu/microsystem-design/www/

4. Prof.K.N.Bhat, IISc Bangalore 4
1) G.T.A. Kovacs, Micromachined Transducers
Sourcebook, WCB McGraw-Hill, 1998
2) J.W. Gardner, Microsensors: principles and
applications, John Wiley & Sons, 1994
3) M. Madou, Principles of Microfabrication, CRC
Press, 1998
Suggested Additional Readings

5. Prof.K.N.Bhat, IISc Bangalore 5
Micro and Smart Systems
Prof K.N.Bhat,
ECE Department , IISc Bangalore
email: knbhat@gmail.com
Lecture -1
Glimpses of Microsystems and Miniaturization

6. Prof.K.N.Bhat, IISc Bangalore 6
What are MEMS and Micro Sytems?
• Micro Electro Mechanical Systems (MEMS ) are
devices that have static or movable components
with some dimensions on the scale of microns
• MEMS combine microelectronics and micro-
mechanics, and sometimes micro-optics
They are referred by different names in different
countries
MEMS : USA
MicroSystems Technology (MST): Europe
Micromachines : Japan
Smart materials and Smart Structures: India

7. Prof.K.N.Bhat, IISc Bangalore 7
Micro Electro Mechanical Systems (MEMS) - Microsystems
Deals with
1.Miniaturization and batch processing of
Sensors , Actuators and microstructures
2. Integration of mechanical components with
electronics
This is a Revolution similar to
VLSI in Microelectronics

8. Prof.K.N.Bhat, IISc Bangalore 8
Batch Processing and miniaturization
Cost Reduction
•Low Power operation
• Biomedical and
aerospace Applications
Reliability &
Reproducibility
Batch Processing
Miniaturization

9. Prof.K.N.Bhat, IISc Bangalore 9
Miniaturization approaches
• Conventional Micromachining
•Silicon Micromachining

10. Prof.K.N.Bhat, IISc Bangalore 10
Conventional Micromachining Techniques
• Each component must be made piece by piece. Low
price for large production volumes are the result of
mechanization.
• Ultrasonic machining, sandblasting, laser ablation and
spark erosion have aided in miniaturization.
• Finest details that can be machined are one to two
orders larger than what photolithography makes
possible.

11. Prof.K.N.Bhat, IISc Bangalore 11
Silicon Micromachining
• Suitable for batch processing similar to
fabrication of ICs.
• Production costs of whole production is
independent from number of components
fabricated.
• Miniaturization with finest details in the range
of 0.1 to 10m possible based on photo-litho-
graphy

12. Prof.K.N.Bhat, IISc Bangalore 12
Classification of MEMS
MEMS structures and devices can be classified into
four major groups:
• Passive (nonmoving) structures (eg) microtips
• Sensors, which respond to the world, (eg) pressure
• Actuators (reciprocal of the sensors), which use
information to influence something in the world.
(eg) pump, valve etc
• Micro-Systems that integrate both sensors and
actuators to provide some useful function

13. Prof.K.N.Bhat, IISc Bangalore 13
Transportation Communications Analytical &
Medical
MEMS
Structures
Infrared
Imagers
Optical & RF
Signal Guides,
Field Emission
Arrays
Micro Filters,
Micro
Channels
& - Mixers
MEMS
Sensors13
13
Pressure ,
Acceleration,
& Angular
Rate
Acoustic
sensors
Gas sensors
MEMS
Actuators
Aerodynamic
Flow
Control13
Displays, Optical
switches, & RF
Switches &
Filters
Micro-pumps
& -Valves
MEMS Categories and Application areas
Categories
Application
Areas

14. Prof.K.N.Bhat, IISc Bangalore 14
Transducers
Sensors Convert
Measured Quantities into
Electrical Signal
Pressure sensor,
Accelerometer, Gyro,
Temperature Sensor, Gas
sensor, Flow sensor
Actuators
Convert different types
of energy into
Mechanical Energy
Micropump, RF
switches and
Resonators, micro
mirror, ES comb drive
Structures AFM tip, Field Emission Arrays,
Micro-fluidic Channels

15. Prof.K.N.Bhat, IISc Bangalore 15
Some Examples of Micromachined
Miniaturized Mechanical component
Pressure
sensors
Micropump
Micro
cantilevers
(DNA Sensor)
Micro
Acceleration
Sensors
RF filters
Nano- tip for
AFM and for
FEA
F ma kx
 
r
k
m
 

16. Prof.K.N.Bhat, IISc Bangalore 16
1.Intracranial Pressure (ICP) and blood pressure monitoring
Need for Miniaturization of Sensors
2.Mapping pressure on
LCA wing
3.Oceanography-CTD sensor
for Marine Engg (NPOL , Kochin)
4. Air pressure and flow in the
ignition system of automobile

17. Prof.K.N.Bhat, IISc Bangalore 17
Piezoresistive pressure sensor
R R R R R
1 2 3 4
   
R
V V
o in R


Pressure P
Diaphragm
Sensitivity
Vo
S
P



Piezo resistors : p-type
boron diffused/ implanted

18. Prof.K.N.Bhat, IISc Bangalore 18
Motorola’s Manifold-absolute Pressure
(MAP) Sensor and schematic of its package

19. Prof.K.N.Bhat, IISc Bangalore 19
A hybrid micromachine
/DNA system (IBM,Zurich)
Silicon cantilever beams for detection of DNA
An array of cantilevers treated
with different strands of DNA.
When a solution containing
different fragments of DNA is
introduced, complementary
strands of DNA will naturally
bind to specific cantilevers
creating stress which deflects the
cantilever.
Can detect damaged DNA
sequences, since a single base
mismatch will cause a slightly
different stress, indicating the
presence of a damaged fragment.

20. Prof.K.N.Bhat, IISc Bangalore 20
Field emission tips for high frequency
Vacuum Electron Devices
Microstructures Micro geras
Micro turbine
Nanometer
size AFM Tip
Need for Miniaturization of structures

21. Prof.K.N.Bhat, IISc Bangalore 21
Micropumps for l/minute pumping
(1) Drug delivery drug dosage control
(2) Lubricating bearings of gyro motor space appln.
Actuation
Mechanism
Pump Diaphragm
Inlet Valve
Pump Chamber
Outlet Valve
Valve Threshold
Pressure p (crit)
Stroke Volume
V
Chamber Pressure p
Chamber Volume Vo
Inlet Outlet
Need for Miniaturization of Actuators

22. Prof.K.N.Bhat, IISc Bangalore 22
Miniaturization is important for Applications
• Biomedical : pressure sensors (Intra Cranial Pressure,
blood pressure) ), cantilever beams (DNA analysis),
micropump ( controlled micro dose of drug Delivery)
• Aerospace and Automobile: Pressure sensors ,
accelerometers,
• Space programs: Pressure sensors , accelerometers,
gyro, micropump
• Micro fluidics channels and mixers: Chemical analysis
and synthesis and lab on Chip concept
• Defense : Explosive detection, gas sensors, pressure
sensors , acceleration sensors and RF MEMS
Microsystems and Miniaturization