A short presentation on MEMS gyroscope. Contents are as below: Gyroscope Gyroscopic Principle Introduction to MEMS MEMS Gyroscope Fundamental Concept and Design Principle Working Principle Fabrication Technologies Applications & Future Scope Conclusion References

1. MEMS GYROSCOPE
BY
PRATIK K. NABRIYA
(UNIV.EXAM.No.T120020891)
GUIDED BY
PROF.S.S.PRABHUNE
SAVITRIBAI PHULE PUNE UNIVERSITY
MAHARASHTRA INSTITUTE OF TECHNOLOGY , PUNE
1Department of Mechanical Engineering

2. Table of Contents
• Gyroscope
• Gyroscopic Principle
• Introduction to MEMS
• MEMS Gyroscope
• Fundamental Concept and Design Principle
• Working Principle
• Fabrication Technologies
• Applications & Future Scope
• Conclusion
• References
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3. What is a Gyroscope ?
• Gyroscope is a device for measuring and maintaining
orientation based on principle of angular momentum.
• Mechanically, Gyroscope is spinning wheel/disc mounted on
axle and axle is free to assume any direction.
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Fig.1. A MECHANICAL GYROSCOPE

4. Gyroscopic Principle :
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Fig.2. GYROSCOPIC PRINCIPLE

5. • Spinning object that is tilted perpendicularly to the
direction of the spin will have a precession.
• The precession keeps the device oriented in a vertical
direction so the angle relative to the reference
surface can be measured.
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Gyroscopic Principle :

6. Applications of conventional
mechanical gyroscopes :
• Aircrafts
• Ships
• Missiles
• Satellites and spacecrafts
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Fig.3. GYROCOMPASS USED IN AIRCRAFTS

7. Introduction to MEMS Technology
• Micro-electromechanical systems (MEMS) technology is a
process technology used to create tiny integrated devices or
systems that combine mechanical and electrical components.
• It combines conventional semiconductor electronics with
beams, gears, accelerometers, gyroscopes, diaphragms levers,
switches, sensors, and heat controllers; all of them
microscopic in size.
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Mechanical Electrical MEMS

8. MEMS Gyroscopes
• Micro-Electro-mechanical Systems (MEMS)
gyroscope is a sensor that measures angle or rate of
rotation.
• In recent years MEMS gyroscopes have gained
popularity for use as rotation rate sensors in
commercial products like ,
- Mobile Handsets
- Automobile
- Game consoles
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9. Why MEMS ?
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Small size
Low Cost
Low Power consumption

10. Fundamental Concept : Coriolis effect
• Coriolis’ Acceleration :
It is an apparent acceleration that arises in rotating frame of
reference. It is proportional to the rate of rotation Ω.
acor = 2(V x Ω)
• Coriolis Force :
Thus the Coriolis force acting on particle of mass ‘ m ’ is given
by :
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Fig .4. ILLUSTRATION OF CORIOLIS EFFECT

12. Fundamental Design Principle :
Drapers tuning fork
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Fig.5. DRAPERS TUNING FORK APPARATUS

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Fig.6. The first working prototype of Drapers Lab comb drive
tuning fork single axis gyroscope (1993)

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15. Working Principle :
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Fig.7. LUMPED STRUCTURAL MODEL OF MEMS
VIBRATORY GYROSCOPE

16. Working Principle :
• Drive mode operation :
• Sense mode operation :
• Combined system of motion :
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Fig.8. AMPLITUDE V/S FREQUENCY GRAPH

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Fig.9. Amplitude Error % V/s Delta F

19. Fabrication Technologies
There are fundamentally two alternative
technologies available for the fabrication of
micromechanical devices:
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Bulk Micromachining
Surface Micromachining

20. Bulk Micromachining
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Fig.10. TYPICAL STEPS IN BULK MCROMACHINING

21. Surface Micromachining
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Fig.11. TYPICAL STEPS INVOLVED IN SURFACE MICROMACHINING

22. Applications & Future Scope
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SMARTPHONES
Precise motion sensing such as user acceleration, angular
velocity and rotation rate.
• Gesture recognition
• Optical Image stabilization.
• Navigation
• Interactive gaming.

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Fig.12.LBS apps on smart phones. Wikitude (left) displays wikipedia
information of the landmark in the camera view. Yelp (right) shows the
distance to nearby restaurants and their on-line rating and reviews.

24. • Fig.13. INTERACTIVE GAMING APPLICATION
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25. Automotive Application
• Yaw rate sensor
• Electronic stability control (ESC ) braking
system.
• Roll rate sensors
• Airbags safety system.
• Vehicle security System.
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Fig.14. Illustration of the angular rate and acceleration
detection axes in automotive applications.

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Fig.15. SegwayTM and
SolowheelTM personal human
transporter.

28. Some Other Similar Applications
Guided and Automatic Missile Systems.
Smart Wheelchair.
Optical Image Stabilization.
Smart Bullet & Ammunition
Satellites stabilization.
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29. Conclusion
• A great deal of engineering goes into design, manufacturing and
implementation of MEMS devices such as gyroscopes.
• MEMS truly bridge gap between electrical and mechanical engineering.
• This presentation was an attempt to understand the fundamental
concepts, working principle and applications of MEMS gyroscopes.
• MEMS fabrication technologies have also been dealt with.
• There is still a lot of room for improvement in current techniques,
especially in reducing drift and increasing sensitivity.
• Future work is to improve mechanical angular rate sensitivity as well as
robustness by 2-DOF drive mode instead of current 1-DOF.
• It is believed that there will be countless other applications discovered for
MEMS gyroscopes in the coming years due to their versatility and size.
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30. References :
• Yeonhwa Jeona, Heejun Kwona, Hyeon Cheol Kima, Sung Wook
“Design and development of a 3-axis micro gyroscope with vibratory ring springs”,
EUROSENSORS 2014, the XXVIII edition.
• Hai Xua*, Jang Ching Chuab, Michael Burtonb, Kefei Zhanga, Franz Konstantin
Fussb,Aleksandar Subicb “Development of low cost on-board velocity and position
measurement system for wheelchair” 8th Conference of the International Sports Engineering
Association (ISEA)
• Cenk Acar, Adam R. Schofield, Alexander A. Trusov, Lynn E. Costlow,, and Andrei M. Shkel,
“Environmentally Robust MEMS Vibratory Gyroscopes for Automotive Applications” IEEE
SENSORS JOURNAL, VOL. 9, NO. 12, DECEMBER 2009
• Zhou Xiaoyao, Zhang Zhiyong, Fan Dapeng “Improved Angular Velocity Estimation Using
MEMS Sensors with Applications in Miniature Inertially Stabilized Platforms” Chinese Journal
of Aeronautics 24 (2011)
• Venkata Ramesh Mamillaa, Kommuri.Sai Chakradhar “Micro Machining For Micro Electro
Mechanical Systems(MEMS)” 3rd International Conference on Materials Processing and
Characterisation
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THANK YOU