Prof.K.N.Bhat, IISc Bangalore 1
Micro and Smart Systems
1. G.K. Ananthasuresh , Mechanical Engineering ,[email protected]
2. K.J. Vinoy, Electrical Communications Engineering, IISc, [email protected]
3. S. Gopalakrishnan, Aerospace Engineering, IISc , [email protected]
4. K.N. Bhat, Electrical Communications Engineering, IISc.
Course coordinators
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
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.htmlhttp://web.mit.edu/microsystem-design/www/
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
Prof.K.N.Bhat, IISc Bangalore 5
Micro and Smart Systems
Prof K.N.Bhat,
ECE Department , IISc Bangalore
email: [email protected]
Lecture -1Glimpses of Microsystems and Miniaturization
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 : JapanSmart materials and Smart Structures: India
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
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
Prof.K.N.Bhat, IISc Bangalore 9
Miniaturization approaches
• Conventional Micromachining
•Silicon Micromachining
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.
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 10m possible based on photo-litho-graphy
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
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 Sensors1313
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
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
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 rkm
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
Prof.K.N.Bhat, IISc Bangalore 17
Piezoresistive pressure sensor
R R R R R1 2 3 4
RV Vo in R
Pressure P
Diaphragm
Sensitivity VoSP
Piezo resistors : p-type boron diffused/ implanted
Prof.K.N.Bhat, IISc Bangalore 18
Motorola’s Manifold-absolute Pressure (MAP) Sensor and schematic of its package
Prof.K.N.Bhat, IISc Bangalore 19A 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.
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
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 ValvePump Chamber
Outlet Valve
Valve Threshold Pressure p (crit)
Stroke Volume
VChamber Pressure p
Chamber Volume Vo
Inlet Outlet
Need for Miniaturization of Actuators
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
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