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MEMS(Microelectromechanical Systems)

Growing in a Shrinking World

A

Seminar on

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CONTENTS

• INTRODUCTION

• MICROMACHINING PROCESSES

• MICROSENSORS AND MICROACTUATORS

• MEMS DEVICES AND APPLICATIONS

• FUTURE PROSPECTS

• CONCLUSION

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INTRODUCTION

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Components of MEMS

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Smart Room

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MEMS PROCESSES

IC Processes

• Oxidation

• Diffusion

• LPCVD

• Photolith

• Epitaxy

• Sputtering

• etc

Micromachining Processes

• Bulk Micromachining

• Surface Micromachining

• Wafer Bonding

• Deep Silicon RIE

• LIGA

• Micromolding

• etc

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Micro-Machining Processes

Micro-Machining

BulkMicro-Machining

SurfaceMicro-Machining

Wafer Bonding Micro-MoldingLIGA

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BULK MICROMACHINING

Wet Etching Dry Etching

Process of removing substrate itself

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Wet Etching

Difference between isotropic and anisotropic etching

All it requires is a container with a liquid solution that will dissolve the material in question

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DRY ETCHING• Reactive ion Etching

• Sputter etching

• Vapour phase etching

Ions are accelerated towards, and react at the surface of material being etched

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SURFACE MICROMACHININGLayers of structural and sacrificial material are

deposited and patterned

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MICRO-MOLDINGTo transfer microscopic shapes

fabricated earlier

(i)Mass Production

(ii) Used for various material including Si

(Sacrificial Layer)

(Structural Layer)

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Micro Sensors and Micro Actuators

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Micro Sensors

• Mechanical Sensors

• Thermal Sensors

• Radiation Sensors

• Magnetic Sensors

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Accelerometer

As device is accelerated, Force developed, Bends the beam

Mechanical Sensors

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RADIATION SENSOR

• PHOTO-DIODE

• Reversed Biased p-n junction diode

• As light falls; charge carriers are generated and more current flows in the circuit

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Micro Actuators

• Electrostatic actuators

• Magnetic actuators

• Piezoelectric actuators

• Hydraulic actuators

• Thermal actuators

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Magnetic Linear Motor

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MEMS Devices and Applications

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Drug Delivery System

• Microcapsules Collapses when exposed to ultrasound

• Simultaneous monitoring

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Micro Pump

• Square Diaphragm 4x4 mm2, 25 µm thick

• Actuator gap 4µm

• Actuator’s frequency 1-100

• At 25 Hz Pumping rate = 70 µl/min.

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Micro-Robot• 9.5 mm diameter, 66 mm long

and 7.3 g weight

• Speed 10 mm/s in 10 mm diameter pipe

• Total power consumption 650 MW

• DENSO CORP. researches for 5.5 mm diameter, 20 mm length and 1 g weight

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Future Prospects

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3 Features of Micro Systems

• Miniaturization is essential.

• Multiplicity is key to successful microsystem.

• Microelectronics is required to move microelements to cooperate with each other and to perform given task.

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SPC MEMS market survey(DARPA sponsored)

YEAR SENSING NON-SENSING

2003 1.8-3.6 B 5-8 B

Janusz Bryzek (Sensorsand Actuators, 1996)

YEAR TOTAL MEMS NON-SENSING

1995 1.45 B 0.05 B

2005 6.7 B 3.4 B

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CHALLENGES AHEAD• The accessibility of Companies both small and large

to MEMS fabrication facility to be increased

• Advanced Simulation and modeling tools for MEMS design are urgently needed

• The packaging of MEMS devices and systems need to improve considerably from it’s current primitive state

• Quality Control Standards for MEMS technology are needed

• The output of well trained MEMS engineers and scientists from the nations university need to increase

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CONCLUSIONSMEMS have been emerging as a new technology in the

past decade. They will continue to develop as an independent technology in the future, while their techniques continue to disperse to other technological fields.

The strategy being proven successful in developing MEMS is: according to the features of the micromachining, attention has been paid to develop MEMS devices that communicate with the outside world through non contact signals, i.e., electrical, magnetic and optical signals.

MEMS will have profound impact on the future society. It is necessary to continue and enhance research activities in both fundamental and application related area. Fusion of knowledge in different disciplines is essential for well balanced accelerated growth of the technology.

I believe since, MEMS is a nascent and synergistic technology, many new applications will emerge, expanding the markets beyond that which is currently identified or known.

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1) Hiroyuki Fujita, Future of actuators and microsystems, Sensors and Actuators, A 56 (1996) 105-111.

2) Minhang Bao, Weiyuan Wang, Future of microelectromechanical systems (MEMS), Sensors and Actuators, A 56 (1996) 135-141.

3) Janusz Bryzek, Impact of MEMS technology on society, Sensors and Actuators, A 56 (1996) 1-9.4) Wayne P. Liu, George H. Brodie, A demonstration of MEMS-based active turbulence

transitioning, International Journal of Heat and Fluid Flow, 21 (2000) 297-303.5) Mehran Mehregany and Andrew S. Dewa, Introduction to MICROELECTROMECHANICAL

SYSTEMS AND THE MULTIUSER MEMS PROCESSES, Part I, MEMS OVERVIEW, Electronics Design Center, Cleveland OH.

6) Mehran Mehregany and Andrew S. Dewa, Introduction to MICROELECTROMECHANICAL SYSTEMS AND THE MULTIUSER MEMS PROCESSES, Part II, SURFACE MICROMACHINING TECHNOLOGY, Electronics Design Center, Cleveland OH

7) Kohji Masuda, Norihiko Tateishi, Eizen Kimura, and Ken Ishihara, Ultrasound DDS using Microcapsules and Visualization of Oxygen Saturation of Oxygen Saturation Levels in Microcirculations, MICROMACHINE No. 37, October 19, 2001.

8) Professor Kazuo Sato, Introductory Course, Latest Micromachining Technology – Part 1. MICROMACHINE No. 33, February 2000.

9) Professor Kazuo Sato, Introductory Course, Latest Micromachining Technology – Part 4. MICROMACHINE No. 34, February 2001.

10) http://home.earthlink.net/11) http://www.dbanks.demon.co.uk/12) http://www.mems-exchange.org/

REFERENCES

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Thank You