IrSens

RTD Project IRSENS

Plenary meeting – Bern – May 12, 2011

Integrated sensing platform for gases and liquids in the near and mid-infrared range

Y. Bonetti, J. Faist ETH Zurich

IrSens

Project Synopsis: NeedsProject Synopsis: Needs

Sensing of small molecules (CO, CO2, NxOy, ...)

Environment(Pollution, Modelling)

Medicine(Diagnosis, Monitoring)

gasfluid

SensitiveSelective

Portable,Low Power

Infrared Spectroscopy Semiconductor System

IrSens

Approach: optical sensing

Laser detector

N O

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holistic approach

QCL,VCSEL Electronics QCD,

SiGe CMOS

Gas

Liquid Yes/No%

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Pilot/focus applications

Gas: CO2 isotope ratios, e.g for plant respiration monitoring – environment

Liquid: Cocaine in saliva detection (presence yes/no) – traffic security

Platform: develop tools and techniquesCollaboration with industry started

IrSens

Measurements in Gases

IrSens

Schematic of the VCSEL gas-sensing demonstrator (TDLS)

in collaboration with IR Microsystems / Leister

Collaboration with an industry

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Cylindrical Multipath Gas Cell

20*20*5 cm3

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Instrumentation benchmarked with different techniques:- Direct Absorption (DA)- Wavelength Modulation (WM)- PhotoAcoustics (PA)

Technique DA (NanoTera)

WM(NanoTera)

PA(NanoTera)

Picarro (CRDS reference)

1s precision (‰) 0.47 0.75 58.8 0.67

best precision (‰) 0.06 (200s) 0.05 (3000s) 0.65 (8000s) 0.1 (300s)

Benchmarking

see poster!

- Prototype cell- wrong QC laser!

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Also software!! full hardware control data acquisition and processing: - real-time fitting module based - on Hitran database measurement automation

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Measurements in Liquids

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Benchmarking with ATR-Spectroscopy

best spectral range for Cocaine in H2O around 1730/cm→ sources and detector design

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QCL 1721 cm-1 measurements

● Strong increase in signal during drying, as expected ● Limit of detection around 20 µg/ml

see poster!

IrSens

Microfluidic Cell

SourceDetector

Inlets andMixer

Outlet

Waveguide

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Transmission through waveguide at 6µm

Detector

ZnSe lens

WaveguideQCL

IMTInstitut de microtechnique

total transmission through 9mm*5µm waveguide: 4 %

see poster!

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Microfluidic Sample Preparation for IR-Detection

Problem µ-flu. requirements Answer

disposable chips low-cost materials and fabrication process

rapid prototyping of UV-glue

mid-IR absorption of water transfer to IR-transparent solvent liquid-liquid extraction

IR-transp. organic solvents used for extraction

chemical compatibility of chip to solvents compatibility tests

aqueous and organic solvents on chip

handling of multiphase flows

adjusting wetting behavior of UV-glue

absorption of analytes materials with high recovery rate absorption tests

fast sample preparation improvement of liquid-liquid extraction

droplet generation & separation

IMTInstitut de microtechnique

see poster!

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Microfluidic Sample Preparation for IR-Detection

IMTInstitut de microtechnique

fluid mixing parameters need good control

IrSens

Support workpackages:

Sources:Vertical cavity surface emitting lasers (EPFL)Quantum Cascade Lasers (ETHZ)

Detectors:Quantum Cascade detectors (UNINE)Ge/Si SPADs (EPFL)

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Low dissipation, cw QC lasers

see poster!

2311cm-1 1730cm-1

1.2W

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Detectors:Quantum cascade detectors,

SiGe CMOS SPAD

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Ge on Si diode test I-V data

low voltage data for diodes with sizes of 1x1, 1x20, and 40x40 micrometer

Breakdown near -40V (criterion of 1 µA)

good material for a detector @ 1.55µm

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Quantum cascade detector

Detectivity 5*108 jones (175K, 2300/cm) and 1.5*107 jones (250K, 1700/cm)

Cold aperture, NTC, black inner side

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Custom-made QCD preamplifier

• Observed 58 dB of gain in 100mV/nA configuration• Roughly 25 times more gain than with commercial solution (PA-9-70 from Judson)• Almost identically low noise as commercial solution

Footprint 4 x 4 cm21kHz 1MHz

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Achievements

Near-IR gas system (VCSEL):– Industrialization in progress

Mid-IR gas– Already reached state of the art

Mid-IR liquid– Key building blocks are validated– New detectors & lasers

Nov

elty

Read iness

IrSens

IrSens teamETH K.Hans, M. SigristY. Bonetti, M. Beck, R. Terazzi, EPFLE. Kapon, A. Sirbu E. Charbon, M.AminianA.Homsy, N. DeRooij,L. Hvozdara, Y-C.Chang, H.P Herzig

EMPAB. Tuzson, A. Manninen, L. Emmenegger

UNINED. HofstetterJ. DiFrancescoFHNWSH. Looser