Transcript Using a Microplasma for Propulsion in Microdevices

Using a
Microplasma for
Propulsion in
Microdevices
David Arndt
Faculty Mentors: Professor
John LaRue and Professor
Richard Nelson
IM-SURE 2006
Outline
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Plasma Pump Introduction
Project Goals
Background
Project Setup and Description
Results
Summary
Future Research Plans
Plasma Pump Introduction
• Air is ionized to
create a plasma.
• Ions move in
response to an
electric field.
• Impart force onto
surrounding air
molecules
Airflow
Copper
Electrodes
Kapton Tape
Project Goals
• Create a working macro-scale plasma pump
• Visualize flow
• Evaluate effect of changing experiment
parameters in order to optimize setup
• Control electrodes independently in order to
control flow direction and path.
• Design and fabricate a MEMS device that
implements a microplasma pump.
Background
• General Micropump Applications
– Manipulating micro-particles and micro volume
fluids.
• Types of micropumps
– Reciprocating: peristaltic pump
– Continuous flow: electrophoresis pump
• Plasma Micropump Applications
– Manipulating gas-carried particles
– Gas sensor
– MEMS cooling
Background
• Inspiration for our
Plasma Pump
Research:
“Using Plasma Actuators For
Separation Control on High
Angle of Attack Airfoils,”
Martiqua L. Post et al.
Project Setup
Top View Diagram
DC Power
Supply
High
Voltage
Plasma
Generator
Smoke
Generator
Power
Supply
Electrodes
Glass Channel
Kapton Tape
Heating
Element
Digital Camera
Project Setup
Channel Models
Large Channel
2.54 cm by 1.4 cm
Small Channel:
2 mm by 2 mm
Results
Velocity Measurements
Results
Velocity Measurements
Setup 5 - Top electrode 12 mm wide
exponential fit
25
30
20
25
velocity (cm/s)
velocity (cm/s)
Setup 4 - top electrode 3 mm wide
exponential fit
15
10
5
0
-2
2
4
6
8
position (cm)
10
5
25
20
15
10
5
0
2
1
2
3
4
5
6
7
No noticeable change in
flow velocity with change
in geometry.
30
1
0
position (cm)
3 mm overlap - both electrodes 20 mm wide exponential fit
velocity (cm/s)
15
0
0
0
20
3
position (cm)
4
5
8
Results
Dielectric Experimentation
• 2 mil Kapton tape
– dielectric strength of 12000 volts.
– 1 layer: minimum voltage enough to burn
Kapton
– 3 layers: works well, very little damage
• 6 mil Cover glass: no noticeable damage
– will be used in MEMS device.
Results
Flow Direction and Path
• Independent
electrode control.
• Used opposing electrode pairs to demonstrate
control of flow direction in a 2 mm by 2 mm channel.
Results
Flow Direction and Path
•Control of Flow Path in a Bifurcating Channel
Summary
• Created macro-scale plasma pump and
visualized air flow.
• Evaluated the effect of electrode width,
electrode overlap and dielectric
material/thickness.
• Demonstrated control of flow path and
direction
Future Research
MEMS Plasma Pump Design and Fabrication
• Overlapping electrodes
• Slide cover glass as dielectric
• Electrodes created by electron beam
deposition and photolithographic patterning
• Channel formed by patterning a clear silicone
material
• Introduce visualization smoke using a
hypodermic needle or create internally
Acknowledgements
Project direction:
Professors John LaRue and Richard Nelson
Technical expertise and advice:
Allen Kine and George Horansky
Research Team:
Eric Cheung, Michael Peng, and Patrick Nguyen Huu