Final Project Presentation for "MEMS"

1. Thermal Actuated Bidirectional
Gear
BY
CHRIS LANEY
SATYABH MISHRA

2. Introduction
MEMS Bidirectional Gear are robust in nature.
It uses Thermal Actuation.
Large output Force, Stictionless Motion and Small Area.
Reliable over a long period of time, in Millions of Cycles.

3. Design
Specifications
Bi-directionality Of Gear
Achieved by thermal actuators
3 Thermal Actuators Used to Actuate and rotate the Gears.
Performance
Frequency ~300Hz
Optimized using square wave DC signal
The DC Signal can be controlled using a PWM IC or using a Simple
Vpulse Signal with (Ton/Ttotal) as the Duty Cycle.

4. SANDIA AutoCAD Design
3D View

5. SANDIA AutoCAD Design
2D Cut View
showing Tunnel

6. SANDIA 3D Model

7. SANDIA 3D Model

8. SANDIA 3D Model
Tunnel View

9. ANSYS Design Test
Maximum
Displacement
=22.154
Micro Meter

10. ANSYS Design Test
Maximum
Von Mises
Stress of
4399

11. ANSYS Animation

12. Advantages
The Gear can be rotated in Clock and Anti-Clockwise Direction.
Very Low Stiction
Improved Displacement
It uses Thermal Actuation
Large Life Cycle and High Temperature Range.

13. Point of Concern
Hard to Design and Fabricate on Chip.
Difficult to Align all the Chevron Actuators together.
Gear is Connected with the help of bar. High Frequency Cooling and
Heating can lead to Connection Error.
Change in Direction : The Gear and Actuator needs to Cool Down , and
move to their Original Shape and Position.

14. References
Sandia Report : Compliant Thermo Mechanical MEMS Actuator LDRD
#52553
R. Cragun and L.L. Howell, “Linear Thermo mechanical
Microactuators,”Microelctromechanical Systems (MEMS), at the 1999
ASME International Mechanical Engineering Congress and Exposition,
pp. 181-188, November, 199

15. QUESTIONS?