A silicon based MEMS resistojet for propelling cubesats
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Transcript of A silicon based MEMS resistojet for propelling cubesats
13-04-23
Challenge the future
DelftUniversity ofTechnology
A silicon-based MEMS resistojet for propelling cubesatsTittu V. Mathew, B.T.C. Zandbergen, M. Mihailovic, J.F. Creemer, P.M. Sarro.
IAC – 11.C4.3.2.
2Titel van de presentatieDelft University of Technology
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Design of a MEMS micro-resistojet
Outline
1. INTRODUCTION 2. DESIGN OF THE THRUSTER
3. FABRICATION USING MEMS TECHNOLOGY
4. TEST RESULTS
5. CONCLUSION
Fabrication using MEMS technology (4/4)
3Titel van de presentatieDelft University of Technology
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Introduction & thesis objective (5/6)
Fabrication using MEMS technology (4/4)
Introduction (1/2)
T3μPS – cold gas micro-propulsion system developed at TUDelft
Delfi-n3Xt – Student designed 3-unit cubesat to be launched in 2012
4Titel van de presentatie
• High thrust-to-power ratio due to high efficiency• Lower system mass – no power processing units needed• Uncharged plume• Usage with wide variety of propellants
Introduction (2/2) Advantages of resistojet over cold gas and ion thrusters
• Lightweight feature• Small structure -> better thermal
response• Easy integration with other
components on a single PCB• Batch fabrication -> reduction of
manufacturing cost• Widely used in commercial
purposes
Advantages of going for MEMS
Fabrication using MEMS technology (4/4)
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5Titel van de presentatie
Design of the thruster (1/2)
Channel width : 50 μmChannel height : 150 μmFin width : 100 μmNozzle throat width : 10 (/5) μmSingle channel design
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Design of the thruster (6/6) Fabrication using MEMS technology (4/4)
6Titel van de presentatie
Design of the thruster (2/2)
Fabrication using MEMS technology (4/4)
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Thrust vs. chamber pressure(Prediction using ideal rocket motor theory)
10 μm nozzle
Chamber pressure [bar]
Th
rust
[m
N]
5 μm nozzle
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Fabrication using MEMS technology (4/4)
8Titel van de presentatie
PECVD SiO2 at both surfaces
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Fabrication using MEMS technology (1/4)
Fabrication using MEMS technology (1/2)
Thermal oxidation of silicon at both surfaces
Aluminium deposition and patterning
First DRIE step from wafer backside
Fabrication using MEMS technology (4/4)
9Titel van de presentatie
Patterning the inlet (2nd DRIE step)
Patterning the channel and nozzle (3rd DRIE step)
Removing SiO2 from the bonding surface; Sealing of the channels by anodic Si-glass wafer bonding
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Fabrication using MEMS technology (2/4)
Inlet manifold
Fabrication using MEMS technology (4/4)
10Titel van de presentatieDelft University of Technology
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Design of a MEMS micro-resistojet
SEM image
Silicon
Single channel
Nozzle throat
Fabrication using MEMS technology (3/4)
Fabrication using MEMS technology (4/4)
11Titel van de presentatieDelft University of Technology
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Fabrication using MEMS technology (4/4)
Silicon
Pyrex
Inlet
Nozzle exit
Packaged device
Needle glues into the inlet manifold
Needle
PCB
Aluminium heater
Nozzle outlet
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Test results without propellant heating (1/3)
Test setup
Fabrication using MEMS technology (4/4)
13Titel van de presentatie
Test results (1/4)
Delft University of Technology
Challenge the future
Design of a MEMS micro-resistojet
5 μm nozzle
10 μm nozzle
Cold gas test results and discussion (2/4)
Test results without propellant heating (2/3)
Fabrication using MEMS technology (4/4)
14Titel van de presentatie
Test results (2/4)
Delft University of Technology
Challenge the future
Design of a MEMS micro-resistojet
Cold gas test results and discussion (4/4)
Throat Reynolds number [-]
Dis
charg
e c
oeff
icie
nt
of
the
nozz
le,
Cd [
-]
Test results without propellant heating (3/3)
Fabrication using MEMS technology (4/4)
5 μm nozzle
10 μm nozzle
15Titel van de presentatie
Test results (3/4)
Delft University of Technology
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Design of a MEMS micro-resistojet
Hot gas test results and discussion (4/6)
Heater temperature [C]
Measu
red
pre
ssu
re [
bar]
Test results with propellant heating (4/6)
Fabrication using MEMS technology (4/4)
5 μm nozzle
10 μm nozzle
16Titel van de presentatie
Challenge the future
Design of a MEMS micro-resistojet
Test results (4/4)
Delft University of Technology
Hot gas test results and discussion (5/6)
Test results with propellant heating (5/6)
Propellant heating efficiency : < 13%
@ mass flow rate of 1 mg/s
Fabrication using MEMS technology (4/4)
Heater temperature [C]
Ele
ctri
c in
pu
t p
ow
er
[W]
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Conclusions & future work (1/2)
Conclusions• Fabricated devices are lightweight (only 162 mg) and dimensions of 25 mm x 5 mm x 1 mm making them very suitable for propelling cubesats • Maximum chamber temperature of 350 ºC achieved with Pel = 2.5 W @ Volt = 10 V
• Specific impulse of 73 sec (without propellant heating) to 104 sec (@ 350 ºC)
• Calculated thrust : 100 μN to 1.2 mN • Effect of low Reynolds number on thruster performance is identified • Technology readiness level of 3 achieved
Fabrication using MEMS technology (4/4)
18Titel van de presentatieDelft University of Technology
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Fabrication using MEMS technology (4/4)
Thank you for attention
Questions ??