Post on 19-Jan-2016
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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sensing and sensors16-722 - S2004
F 9a30-12p20 NSH1305
Jen Morris <jenmorris@cmu.edu>
+1 412 268 3303
office: HH A313
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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L2004-10A
Solid-state Chemical Sensors and Chemical Sensor Arrays
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Bibliography
• Figaro Engineering, Inc. – http://www.figarosensor.com/
• MicroChemical Systems SA– http://www.microchemical.com/– http://www.sensors.com.cn/download/MiCS/
• Cyrano Sciences, Inc.– http://cyranosciences.com/
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Solid-State Chemical Sensors
• Metal-oxide semiconductor layer– Usually tin dioxide (SnO2)
• Apply heat – In air
• Surface oxygen increases (negatively charged)• Resistance increases
– In presence of deoxidizing gas• Surface oxygen decreases• Resistance decreases
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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How They Work
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Figaro Engineering, Inc.
• Chemical gas sensors– LP-Gas/Propane (500-10000ppm)
– Natural gas/Methane (500-10000ppm)
– General combustible gas (500-10000ppm)
– Hydrogen (50-1000ppm)
– Carbon monoxide (50-1000ppm)
– Ammonia (30-300ppm)
– Hydrogen sulfide (5-100ppm)
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Figaro TGS 2442
• Carbon Monoxide Sensor
• Applications:– CO detectors– Air quality controllers– Indoor parking lot ventilation
• Gas sensing layer– Tin dioxide (SnO2)
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Figaro TGS 2442• Features:
– Low power consumption
– High sensitivity/selectivity to carbon monoxide (CO)
– Miniature size
– Low sensitivity to alcohol vapor
– Long life and low cost
– Low humidity dependency
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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TGS 2442 Basic Measuring Circuit
• 1 second heating cycle• 1 second circuit voltage cycle
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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TGS 2442 Specifications
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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SnO2 for CO Sensing
• Rs = Sensor resistance of displayed gases • Ro = Sensor resistance in 100ppm CO
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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SnO2 for CO Sensing
• Rs = Sensor resistance at 30ppm, 100ppm and 300ppmof CO at various temperatures and 50%R.H.
• Ro = Sensor resistance at 300ppm of CO at 25°C and 50% R.H.
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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MicroChemical Systems SA
• Chemical gas sensors– Ozone (0.01-10ppm) – Nitrogen Dioxide (0.05-5ppm) – Ethanol (50-1000ppm)
– CO / NO2 (1-400ppm/0.05-5ppm)
– Carbon Monoxide & HCs (1-400ppm)
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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MicroChemical Systems MiCS-3110
• Ethanol Sensor
• Applications:– Breathalizer: (Blood Alcohol Content)– Various industrial applications
• Gas sensing layer– Tin dioxide (SnO2)
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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MicroChemical Systems MiCS-3110• Features:
– Low heater current
– Wide detection range
– High sensitivity
– Fast thermal response
– Electro-Static Discharge protected
– Miniature dimensions
– High resistance to shocks and vibrations
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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MiCS-3110 Basic Measuring Circuit
• Run in constant voltage mode• Heater voltage of VH = 2.4 V
– increases temperature of Rs to 430°C
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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MiCS-3110 Specifications
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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SnO2 for Ethanol Sensing
• RS = Sensor resistance to C2H5OH • R10ppm = Sensor resistance resistance in 10 ppm of C2H5OH
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Chemical Sensor Arrays
• Array of polymer composite sensors
• Swell in presence of vaporized analyte– Conductive polymer pathways broken– Resistance increases
• Different gases produce different responses
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Cyrano Sciences, Inc. Cyranose® 320
• Hand-held chemical vapor sensor
• 32 thin-film carbon-black chemiresistors
• Trained by taking different measurements– Create a database of patterns– Match odors against saved patterns
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Cyranose® 320 Specifications
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Cyrano Sciences, Inc. NoseChipTM
• Under development– Low cost, low power, lightweight sensing – Optional short-range wireless capability
• Applications– Sensing nodes for facilities protection – Personal badge detectors for toxic
industrial chemicals and chemical warfare agents
– Residual life indication – Leak detectors in military or commercial
systems – Quality monitors in embedded systems
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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NoseChipTM Specifications
jenmorris@cmu.edu 16-722 L2004-10A (solid-state chemical sensors)
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Bibliography
• Figaro Engineering, Inc. – http://www.figarosensor.com/
• MicroChemical Systems SA– http://www.microchemical.com/– http://www.sensors.com.cn/download/MiCS/
• Cyrano Sciences, Inc.– http://cyranosciences.com/