1. Modeling a Novel MEMS Gyroscope
Nilgoon Zarei
Prof. John Jones
Prof. Albert Leung
8-May- 2012

2. Background & Introduction Theory Comsol Design Simulation Results
Overview
Background & Introduction
Theory
Comsol Design
Simulation Results
Prototype Fabrication and Design steps
Conclusion
Future Work
Reference

3. Introduction Thermal gyroscope What is a gyroscope?
Gyroscope is a sensor which monitors rotation.
Two categories:
Conventional gyroscope
Fiber Optic Gyroscope
Ring Laser Gyroscope
2. MEMS gyroscope
Capacitor gyroscope
Thermal gyroscope

4. Advantage of MEMS Gyroscope
Lower cost
Lower weight
Higher sensitivity
Wider range of application
Aerospace, spacecraft & satellites
Military
Cell phone and cameras
Automobile industry

5. No proof mass Advantage of Thermal MEMS Gyroscope No mechanical stress
No wearing
Higher sensitivity
Lowest cost
Disadvantage: Acceleration signal will produce significant impact on output signal

6. Theory and background
Fundamental operating principle of the Thermal Gyroscope is the Coriolis Force
[1] NSERC USRA, Albert Leung
Warm air bubble travels from one heater to the other. With a fixed gyro, the bubble travels in a straight line. With rotation, the air bubble will deviate towards one of the sensors.

7. Initial gyro design Oscillating flow + Output signal Heater 1 -
Variable resistors detect hot air deflection resulting from Coriolis Effect

8. Simulation results
Find ΔT in two cases, rotation and non-rotation, then calculate their difference.

9. Simulation results θ
Sensor
Results depends on θ

10. New Gyro design Hot sensor 1 Oscillating flow Hot sensor 2
In this design we don’t have heaters
To reduce the impact of buoyancy force

11. Output signal and rotation relation
Linear relation between ω and output signal

12. θ

13. Fabrication process of building Thermal gyroPt OX Si

14. Fabrication process of building Thermal gyroPt OX Si

15. Fabrication process of building Thermal gyroPt OX Si

16. Fabrication process of building Thermal gyroPt OX Si

17. Fabrication process of building Thermal gyro
Sensor resistance : 4.8K Ω
Heater resistance : 600K Ω
Devised mask

18. Experimental Work
Pump
Output signal

19. Conclusion : Operation of thermal gyro demonstrated
Force convection model based on heater sensor, is a reliable model
It is possible to monitor rotation independent from θ
We have fabricated a sensor and run experimental work to confirm simulation results

20. Future work Continuing the experimental work
Building a rotary stage for experimenting rotation

21. References
A.M. Leung, A Low-Cost Thermal MEMS Gyroscope, Hilton Head Workshop 2010: A Solid-State Sensors, Actuators and Microsystems Workshop, pp , Hilton Head Island, South Carolina, USA, June 6-10, 2010.
Design and Analysis of a Micromachined Gyroscope : SPIE Conference, San Francisco, California, USA, 2011

22. Thank you