NPTEL ( Micro and Smart Systems) · Optical & RF Signal Guides, Field Emission Arrays Micro Filters, Micro Channels & - Mixers MEMS Sensors13 13 Pressure , Acceleration, & Angular

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.

[email protected]

Course coordinators


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


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/


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


Micro and Smart Systems

Prof K.N.Bhat,

ECE Department , IISc Bangalore

email: [email protected]

Lecture -1Glimpses of Microsystems and Miniaturization


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


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


Batch Processing and miniaturization

Cost Reduction

•Low Power operation

• Biomedical and aerospace Applications

Reliability & Reproducibility

Batch Processing

Miniaturization


Miniaturization approaches

• Conventional Micromachining

•Silicon Micromachining


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.


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


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


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


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


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


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


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


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.


Field emission tips for high frequency Vacuum Electron Devices

Microstructures Micro geras

Micro turbine

Nanometer size AFM Tip

Need for Miniaturization of structures


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


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

Documents

NPTEL ( Micro and Smart Systems) · Optical & RF Signal Guides, Field Emission Arrays Micro Filters, Micro Channels & - Mixers MEMS Sensors13 13 Pressure , Acceleration, & Angular