Presentation on theme: "MSD1 Senior Design Project- Oxygen Gas Sensor"— Presentation transcript:
1 MSD1 Senior Design Project- Oxygen Gas Sensor Samuel ShinJeremy GoodmanSponsor: RIT uE & EE departmentProject Guide: Professor Slack
2 Agenda Project description High Level Customer Needs/ Eng Specs Concept Description & RationaleSystem ArchitectureHigh Risk AssessmentDetailed AssemblyEmitter and Receiver CircuitPhotodiode FabricationTesting ResultsFuture Plans
3 Project Description Oxygen gas detection via fluorescence quenching. Based on Tris-Ruthenium[II](dichloride) material incorporated in an oxygen-permeable polymerResponds to gaseous %Oxygen which changes fluorescent intensity and lifetimeHigher O2 conc = decreased intensity and lifetimeMethod has been researched and is widely usedExpensiveEquipment not readily available to everyday userPlan is to design a complete cost & size- efficient sensor system for the measurement of % Oxygen
4 High Level Customer Needs / Eng Specs Provide consistent measurement resultsLED pulse width at 100msEntering wavelength at 455nmCost and size-effectiveCommercially available LED sourceStandard electronic components for signal conditioningLow-cost, high performance optical filtersRIT SMFL designed/built photodetectorRu(dpp) polymer created in RIT Chem dept.
5 Concept Description/ Rationale Incorporate the entire system inside a light-tight boxInject fixed amounts of nitrogen and oxygen to exhibit an environment with fixed %Oxygen
6 System ArchitectureInput Signal (100ms pulse width from function generator)LED Pulsing Circuit (455nm)Ru(dpp) Thin Film (fluorescent material) – emitting wavelength of 613nmOptical & Signal ConditioningAmplified Signal in Oscilloscope (I or V vs. Time)
7 High Risk Assessment Still a proof of concept Materials Funding Design will have to be modified to match needsUnclear Parameters will existWhere noise is coming from, etcMaterialsCreating Ru(dpp) polymer has to be done with help from a faculty memberFundingAssembly of chamber, gas canisters needed.Difficult to obtain funds
8 Final Results- LED Emitter Circuit Circuit assembled to exhibit a steady source of LED light, in a set fixed pulse.Used a power PMOSFETCompleted assembly using vectoboard and soldering components.
9 Final Results- Receiver Circuit Circuit assembled to receive the light source and transfer it into voltage output.Used photovoltaic amplifier circuit configuration.Completed assembly using vectoboard and soldering components.Completed circuit demonstration in lab, and also with complete light- tight box.Used commercial photodiode for test.
10 Photodiode Planning Two Architectures – 4” n-type silicon Lateral (Finger) DiodeSmall Active AreaFast Response TimePlanar DiodeLarge Active AreaSlow Response TimeTunable Junction Depth (Wavelength Selectable)Fabricated in the RIT SMFL
15 Photodiode Results - Responsivity Planar responsivity >2x greater than Lateral!↑ Active AreaTuned Junction↑ ResponsivityGREATER SIGNAL!BUT↑ DARK CURRENT!PLANAR>2xDifferenceResponsivity (A/W)LATERALWavelength
16 Photodiode Results - Capacitance Planar capacitance much higher than Lateral↑ Surface Area↑ Capacitance↑ Response TimeSLOWER DIODE!PLANARLATERAL
17 Photodiode Conclusion Planar diode had increased responsivityHigher Signal from Fluorescence SignalHigher Dark CurrentLateral diode had low capacitanceFast Response TimePlanar likely candidate for Fluorescence Spec.
18 Testing ResultsPlan was to assemble a tight flow chamber with valves with oxygen and nitrogen flowing in.Emitter and receiver circuit showed proper required behavior as outlined in specifications and customer needs.Limited testing environment available, but still showed a change in intensity, as specified.
19 Strong / Weak Points of Design/ Room for future research & improvement Strong points of final designWas able to exhibit a possible, more affordable alternative.Introduced cost effective fabrication method of photodiode.Weak points & places for improvementsActual testing of chamber incompleteAbnormal behavior in emitter circuitNeeded more people in respective fieldsNeeded more funding
20 Conclusion Project description High Level Customer Needs/ Eng Specs Concept Description & RationaleSystem ArchitectureHigh Risk AssessmentDetailed AssemblyEmitter and Receiver CircuitPhotodiode FabricationTesting ResultsStrengths & weakness of design, plans for future research