ir (infrared) night vision weapon detection security monitoring firefighting
TRANSCRIPT
IR (Infrared) Night VisionIR (Infrared) Night Vision
Weapon Detection
Security Monitoring
Firefighting
IR SensingIR Sensing
– Photonic – absorbed photon excites electronic transitions• Cryogenic cooled (77K) • Most sensitive IR sensor (NETD = 5mK)
– Thermal – absorbed radiation changes device temperature
• Operate at room temperature (uncooled)• Less sensitive (NETD ~ 20 mK)
Thermal IR sensors
Supporting Leg
SensorRadiation Signal
Supporting Substrate
CCD
BeamSplitter
Low PowerVisible Laser
ImagingLens
Focal Plane Array (FPA) of Bi-material Cantilever Temperature Sensors
Infrared (IR)Source
IR AntireflectionCoating
IR Absorber
VisibleReflector
FPA SideView
IR Radiation
ImagePlane
Image Process System
InfraredLens
Cantilever IR Sensor ArraysCantilever IR Sensor Arrays
Cantilever DesignCantilever Design
• Material selection – SiNx/Al
• IR optics ( SiNx )– Resonant cavity (m / 2)
• Thermal design– IR absorption area– Minimum thermal conductance
• Thermomechanical design– Long bimaterial beam– Vacuum Packaging
Bi-material Cantilever
Anchor
Thermal Isolation Leg
Si SubstrateIR absorber
Microfabrication ProcessMicrofabrication Process
• High temperature process• Metal deposition simultaneously on both
layers after release
Si substrate
LPCVD PSG
LPCVD SiNx
LPCVD Poly Si
Al
Pt
18
10121416
20
(oC)Pixel size: 110 m
Pixel Layout and Pixel Layout and Temperature ResponseTemperature Response
Thermomechanical Response ~ 2 m/K
Experiment Setup and IR Imaging ResultExperiment Setup and IR Imaging Result
CCD
He-Ne Laser
Beam Splitter
FPA
Vacuum Chamber
Temperature Control System
IR Lens
Beam Expander
Imaging Lens
IR imaging with background subtraction
Linearization CalibrationLinearization Calibration
Original image Linearly corrected
Zhao, Mao, Horowitz, Majumdar, Varesi, Norton, Kitching, J. MEMS (2001)
Summary
10 m
• Nanotube
• Thermal Imaging
• Cancer Detection
• IR Night Vision
An Example for ME381R:Micro-Nano Thermal-Fluid
Science and Technology