Long stroke out-of-plane actuator using combination of electrostatic and pneumatic forces

1. LONG STROKE OUT-OF-PLANE ACTUATOR
USING COMBINATION OF ELECTROSTATIC
AND PNEUMATIC FORCES
MEMS 2014
Tetsuo Kan1, Akihiro Isozaki1, Hidetoshi Takahashi1, Kiyoshi Matsumoto2, and Isao Shimoyama1, 2
1Department of Mechano-Informatics, Graduate School of Information Science and Technology,
The University of Tokyo, Tokyo, Japan
2IRT Research Initiative, The University of Tokyo, Tokyo, Japan
Presenter: Chung-Wei Huang
2015.04.28

2. OUTLINE
Introduction
• electrostatic actuation
• pull-in effect
• pneumatic actuation
Design
Actuation procedure
Fabrication& Experimental setup
Experimental results
Conclusion

3. INTRODUCTION-1
• Advantages:
1.Low power consumption
2.Fast response
• Disadvantage:
Pull-in effect→ limit stroke length
 Electrostatic actuation

4. INTRODUCTION-2
 Electrostatic actuation
http://www.memsolver.com/Help/tochtml/combdr.htm
In-plane Out-of-plane
moving parallel to the substrate moving vertical to the substrate
e.g. comb actuators e.g. vertical comb
Jin-Chern Chiou et al, 2007 Tetsuo Kan et al, 2013

5. INTRODUCTION-3
 Pull-in effect
k
x
y
w
g
deflection
constantspring
F:forcespring
V
)-(g
A
2
1
F:forceticelectrosta
s
2
2e




δ
k
kδ


Fs
Fe
deflection
force
Increasing voltage

6. INTRODUCTION-4
 Pneumatic actuation
Microvalve ActuatorMicropump
G. B. Lee et al, 2006 Armin Werber et al, 2008Fundamentals and Applications of Microfluidics

7. DESIGN
 Spiral structure
 Electrostatic force +pneumatic force

8. ACTUATION PROCEDURE
 Instability
1.Electrostatic actuation
→pull-in effect
2.Pneumatic actuation
→ fluttering

9. FABRICATION & EXPERIMENTAL SETUP
 Fabrication  Experimental setup

10. Altering pressure Altering voltage
EXPERIMENTAL RESULTS-1
 Displacement measurement
103 𝜇𝑚

11. EXPERIMENTAL RESULTS-2
 Dependency on the spiral dimensions
s1:Spiral without a disk
s2:Disk diameter 60 𝜇𝑚
s3:Disk diameter 80 𝜇𝑚
s4:Disk diameter 90 𝜇𝑚

12. CONCLUSTION
• This work presents a new idea using two types of actuation to
drive the structure simultaneously and get a large stroke length.
→maximum displacement: 103 μm.
• The fabrication of the actuator using SOI process and verify the
results of the concept of the new driving type.
• Application: optical systems.

13. THANK YOU.

14. 2
2
22
V
)-(g
A
2
1
V
C
2
1
)CV
2
1
(
Work
F












xxx
2
)-2k(g
A


δ →curve
gk
k
3
1
)-(g
AV
0
)-(g
AVFnet
3
2
3
2










→find max
→relationship between gap and deflection
kδ 2
2net V
)-(g
A
2
1
F



15. EXPERIMENTAL RESULTS-3
 Mechanical resonance
Experiment Simulation