BE Final - PPT
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Transcript of BE Final - PPT
Design of a
Novel MEMS Based Acoustic Filter
for Gunshot Detection
PROJECT GUIDE: Dr. Gautam S. Chandekar
GROUP MEMBERS: Neha Sharma B80200865
Tejaswita Patil B80200864
Ishita Mukherjee B80200825
Pooja Shivale Patil B80200826
Outline
1. Work Statement
2. Project Hypothesis
3. Gun Shot Trials
4. Numerical Analysis
5. Analytical Understanding
6. Fabrication
7. Packaging
8. Testing
9. Conclusion and Future Scope
10. Time Frame, Budget and Company Profile
Work Statement
Problem statement:
To Design and Develop a Novel MEMS based Sensor to
detect Acoustic Signature of Gun Shot
Why:
• Traditionally available and currently under research v/s
MEMS based concept sensor
• Defense v/s Civil Applications
Where:
‘Sookshma’, Microsystems Labs,
R&DE (Engrs.), Dighi, Pune
Diaphragm
Silicon
Dioxide Layer
Handle Layer
Etched out
Void Cavity
MEMS
Acoustic
Sensor
Project Hypothesis
Unidirectional
Microphone
Packaging
Trials – Setup
‘Saksham’, Robotics Development Centre testing ground
7 microphones each 2 meters apart
‘Daksh’ – Master Control Station
Microphones positioning (Contd.)
Test 3
Test 4
2 m
5 m 30 m
12 m
2 m
5 m 30 m12 m
5 m
94
9596
92
94
9596
92
Numerical Analysis
Software support: SOLIDWORKS 2011, ProENGINEER Wildfire 4.0,
ANSYS WORKBENCH 14.0
At Fabrication Lab ‘Sookshma’
• Processes (chemicals)
• Cleaning
• Wet etching (TMAH)
• Sputtering (Ar gas
atm.)
• UV LIGA
• Spin Coating (SU8)
• Equipments (chemicals)
• SEM-Scanning
Electron Microscope
• Oxidation Furnace
• Chemical Workbench
• Reflux Water bath (as
manufactured)
Class 1000 and Class 10,000 cleanroom facilities
Fabrication Initiation
[MEMS Mechanical Sensors, Stephen Beeby]
Thermally grown oxide layer on 2” Si wafer
Spin coat +ve photoresist using a set recipe
(both sides)
UV Lithography to pattern the mask on
properly aligned wafer
Etch SiO2 with bHF Etchant (SAFETY IMP!)
Strip photoresist by acetone
Major Flat <110>
Wafer Surface
<100>
Testing – Characteristics
0
1
2
3
4
5
6
7
8
Amplitude (V)
Output Frequency (Hz)
Output Freq. = Input Freq.
Output Freq. | (With diaphragm = Without Diaphragm)
Low Amplitude generated by Freq. Generator at Low Freq.
Temporary Packaging => Inadequate Sealing
Concluding Remarks
Peak Amplitude FFT Peak Frequency = 380 Hz
SiO2 material wafers
3D printed plastic model
Trial o/p Characteristics Plot range shifted due to
leakage and low amplitude
• Small size
• Fab. – fast, efficient,
less complicated
• Simplified, fast
• Matl. compromised
• Accuracy drop
Future Scope
Hermetically sealed metal package with glass
to metal seals welded to it to best suit military
applications
Vary diaphragm attaching &/or mounting
techniques
Align diaphragms in Arrays or Cubical
orientation for directionality & vector sensing
Time Frame Followed
Work/Month Aug Sept Oct Nov Dec Jan Feb Mar AprMayJune
Software
Design inputs
Design/
Prototyping
Analysis/
Univ. Exam.
Fabrication
Packaging
Report
writing
Final Split-Up Budget
Sr. No. Items Units Cost/Unit (Rs.) Total Cost (Rs.)
1 Si Wafer ( 2”) 10 3000 30,000
2 Microphones (Condenser
type)
10 500 5000
3 Signal Conditioning Module 1 30,000 30,000
4 Chemicals and Echants NA NA 5000
5 Packaging Material NA NA 8000
6 Others (Travelling, etc.) NA NA 2000
Total Cost 80,000
R&DE (Engrs.), Dighi, Pune
Formed: 1958
[Technical Development Establishment +
Directorate Technical Development and Production]merging with Defence Science Organization
Works under:
Defence Research and Development of Ministry of Defence
Undertakes:
Design and Development of world class weapon systemsand equipment
Known for:
Projects in Avionics, Light Combat Aircraft, UnmannedAerial Vehicles, Radar Warning Receivers, Tanks, Bridges,and so on…