Advances in miniaturespectrometer and sensordevelopment
Jouko Malinen
VTT Technical Research Centre of Finland
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
205/05/2014 2
Co-authors
Dr. Anna Rissanen MEMS FPI technoloyDr. Heikki Saari Piezo-actuated FPI and hyperspectral
technologyDr. Mikko Karppinen Spectrometer integrationDr. Pentti Karioja R2R printed sensorsDr. Timo Aalto Silicon photonicsMr. Kari Tukkiniemi ASIC design
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
305/05/2014 3
Outline
Why miniatureFabry-Perot tunable filterMEMS spectral enginesSpectrometer integrationPiezo-actuated FPIEmerging sensor developments
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
405/05/2014 4
Motivation for miniaturization
• Miniaturizing spectrometers into hand held-mobile-connected sensorscreates opportunity for novel applications:
Cost critical process on-line measurementsEnvironmental sensing (Internet of Things)Gas sensingHealth and wellness, diagnostics
From benchtop to handheld
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
505/05/2014 5
Introduction – Fabry Perot interferometer
SPIE Next Generation Spectroscopic Technologies 2014
Basic equation for transmitted wavelengths:= 2d/m
Passband = 430 nm
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
605/05/2014 6
PIEZO-ACTUATED
Large aperture sizes, ~20 mmAccurate gap control through integratedcapacitance measurement
Easily customizedFor low to medium annual volumes
MEMS
Optical apertures up to ~2 mmSuperior mirror flatnessInsensitive to vibrations or positioningLow operational voltagesFor medium to high annual volumes
The two filter platforms - summary
SPIE Next Generation Spectroscopic Technologies 2014
MEMS spectral engines
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
805/05/2014 8
MEMS spectrometer development andcommercialization at VTT
20 year development effort, 15M€+ investment, 100 man yearsMEMS-FPI solutions covering UV-VIS-NIR-IR-TIR, 350nm – 12 µmSupporting patent portfolioPartners: Vaisala, VTT Memsfab, Spectral Engines …
SPIE Next Generation Spectroscopic Technologies 2014
1997 - 2003
VaisalaCarboCap
2009
Fuel qualitysensorEthylene
sensor forESA
20122006
GasSensor
2014
ImagerPen
spectrometerImaging
platform dvlpt
memsNIR
2013
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
905/05/2014 9
MEMS FPI process platforms & wavelengths
NIR/MIR FPIUV/visible FPI
Ultra-compact chip spectrometer
MIR/TIR FPI
UV200 – 350 nm
Visible350 – 800 nm
Low NIR0.8 – 1.1µm
Near IR1,1 – 2,5 µm
Mid IR3 – 7 µm
Thermal IR7 – 12 µm
Wav
elen
gth
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1005/05/2014 10
Moisture in paper (0.1, 3.5 and 10.1%)
Wavelength ranges1.3 - 1.7 µm1.6 - 2.0 µm1.7 - 2.2 µm
Resolution(% of wavelength)1 0.7-1.4 %
Wavelength settling time < 0.8 ms
SNR (typical) 3000
Power consumption < 1 W
Optical interface SMA 905
Input fiber core diameter Max. 400 µm diam.
Numerical aperture 0.22
Wavelength stability < 0.1 nm / C
Dynamic range > 15 bits
Size 50 x 35 x 20 mm3
Weight < 50 g
Operating temperature range +10..+35 C
memsNIR prototype
SPIE Next Generation Spectroscopic Technologies 2014
NIR spectrometer engine
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1105/05/2014 11
MEMS hydrocarbon gas sensor
Main characteristicsWavelength range 3000-3500 nm
Spectral resolution 50-60 nm
Optical path length 17 mm
Spectrum acquisitiontime
2 s (10 spectralpoints)
Power consumption(continuous mode) < 2 W
Size 77 x 38 x25 mm
Weight 95 g
Mannila R., Tuohiniemi , M., Mäkynen, J., Näkki, I., Antila, J., "Hydrocarbon gas detection withmicroelectromechanical Fabry-Perot interferometer ", Proc. SPIE 8726, 872608 (2013).
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1205/05/2014 12
Wavelength range from 7.5 µm to 9.5 µmControl voltage from 0-30VFWHM of 140nmAperture size 1.2 mm/4 layers of polysilicon-air-polysilicon
Mirrorstructure
Thermal IR MEMS Fabry-PerotInterferometer
MEMS FPI cross sectionTuohiniemi, M., Blomberg, M., Akujärvi, A., Antila, J., Saari, H., “Optical transmission performance of a surface-micromachinedFabry-Pérot interferometer for thermal infrared” J. Micromech. Microeng. Vol. 22(11), 115004, (2012).
Tuohiniemi, M., Näsilä, A., Mäkynen, J., “Characterization of the tuning performance of a micro-machined Fabry-Pérotinterferometer for thermal infrared”, J. Micromech. Microeng. Vol. 23 (7), 075011, (2013).
MEMS FPI characterization
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1305/05/2014 13
Spectrometer performanceat sensor price point
Spin-off starting from VTT
www.spectralengines.comSPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
14
Spectrometer integration
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1505/05/2014 15
Competences and challenges for miniaturization
High-precisionalignment(passive or active;e.g. fiber pigtailing)
Encapsulation(hermetic sealing,windows)
3D integration andpackaging(electronics,bare die mountinggas/liquid channels,…)
Thermal management(CTE matching,temperature control,minimized dissipation)
SPIE Next Generation Spectroscopic Technologies 2014
Electronicsintegration(performance, EMIissues)
Silicon photonics(propagation losses,optical throughput,polarization)
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1605/05/2014 16
System-on-package: mid-IR gas analyzer
SPIE Next Generation Spectroscopic Technologies 2014
10 cm
Test setup
Protosensor head
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
17
Piezo-actuated FPI -spectrometers andhyperspectral cameras
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1805/05/2014 18
Piezo-FPI platform
Piezo-actuator tuneable FPI assembled from MEMS-based reflectorsSmall- to medium volume productionEasy customization and fast device prototypingcompared to MEMSLarge optical aperture provides excellent sensitivityLarge tuning range with single elementRobust construction (tested for space requirements)Wavelengths from UV to thermal IR
UV200 – 350 nm
Visible350 – 800 nm
Low NIR0.8 – 1.1µm
Near IR1,1 – 2,5 µm
Mid IR3 – 7 µm
Thermal IR7 – 12 µm
Wav
elen
gth
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
1905/05/2014 19
VIS-VNIR hyperspectral camera
Light-weight (~0.5 kg): can beoperated with low-cost UAVsWavelength range 500 - 900 nmWavelength resolution 10 nmCMOS image sensor 1 – 5 Mpix
Publications:Saari, H et al, “Unmanned Aerial Vehicle(UAV) operated spectral camera system forforest and agriculture applications”, Proc.SPIE 8174 (2011).
Smallbiomass
Largebiomass
Commerciallyavailable:
www.rikola.fi
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2005/05/2014 20
VIS-VNIR hyperspectral camera in medicalapplication studies
VTT’s camera can detect skin cancer within secondsEasy-to-use hand held instrumentFast screening and early detection of skin cancerApplication being studied at the University of Jyväskylä
Wavelength range:500-900 nm
Wavelength resolution:Ca. 10-30 nm
Spatial resolution:2 Mpix
Development status:• 1st generation
prototype done• Application studies
ongoing
Neittaanmäki-Perttu, N., Grönroos, M., Tani, T., Pölönen, I., Ranki, A., Saksela, O.and Snellman, E., “Detecting Field Cancerization using Hyperspectral ImagingSystem”, accepted for publication in Lasers in Surgery & Medicine Journal in June2013.
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2105/05/2014 21
Wavelength ranges of Piezo-FPIand image sensors
SPIE Next Generation Spectroscopic Technologies 2014
Available, dielectric mirrors
Available, metallic mirrors
Customizable, dielectric mirrors
Wavelength (µm)
1 10.2 .3 .4 .6 .8 2 3 4 6 8 11 12 141 10
Wavelength (µm)
1 10.2 .3 .4 .6 .8 2 3 4 6 8 11 12 141 10
Metallic FPImirrors
Dielectric FPImirrors
Dielectric FPImirrors
CMOS&CCD
InGaAsExt-InGaAs
InSbMCT
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2205/05/2014 22
Stand-off Raman spectroscopy at FOI withUV-FPI
Precise selection of Raman shiftsin combination with high out-of-band blockingWorks in the UV range where nocomparable filtering systems arecommercially availableCompact, high resolution (~0.2 nm@ FWHM) UV-FPIModule operation stable undervarying environmental conditions
Glimtoft, M., Bååth, P., Östmark , H., Saari, H., Mäkynen, J., Näsilä, A.,“Towards eye-safe standoff Raman imaging systems”, SPIE Proceedings 9072,(2014).
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2305/05/2014 23
Large aperture piezo-FPI gas sensors
Separately assembled Mid-IR FPI tunable filter platforms forMulti-gas measurementsCorrelation spectroscopy
Large apertures provide high optical throughputApplication testing with an industrial gas analysis systemQuantitative multi-gas analysis possible
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2405/05/2014 24
Single-Band Tunable FPI Filter Platform
Replacement for filter wheelBragg mirrors fabricated onsilicon wafersCapacitive air gapmeasurement and off-the-shelf piezos for actuationDedicated assembly andcalibration procedureTunability: 4-5 µmSpectral resolution (wideband due to applicationneed): ~70 nm (FWHM)
Air gap
Piezoactuation
Electrodes
n=1..2air gap=2..3 µm
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2505/05/2014 25
Correlation Spectroscopy FPI Platform
Correlation spectroscopy forhigh sensitivityAir gap in millimeters (highdiffraction order)Spacers provide small gap foraccurate capacitivemeasurementTransmission pattern mimicsabsorption of COTunability for correlation andanti-correlation with CO
Air gap
Spacers
Piezoactuation
Electrodes
n=~550air gap=~1.2 mm
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
26
Emerging sensordevelopments
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2705/05/2014 27
Printed and Hybrid Functionalities research at VTTResearch Focus
From printed components to printed and hybrid systemsSolutions
Technology (material development and tuning, process planning and design,device and systems designs and modelling) and business development services,examples:
Printed solar cells, lighting solutions (ILEDs, OLEDs), printed transistors,printed sensors and indicators, printed power sources, nanoparticles andfunctional inks
Scaling up services using printing and hybrid pilot lines
Benefit to CustomersNew thin flexible product concepts made possibleHelp in finding new business opportunities availableLow risk for scaling up production
SPIE Next Generation Spectroscopic Technologies 2014
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
2805/05/2014 28
Nanoimprint lithography NIL
SPIE Next Generation Spectroscopic Technologies 2014
UV nanoimprint process Roll to roll UV-imprinting process
Sheet level R2R UV-replication
Current status 3 … 5 1.5 … 2
R&D status 4 … 7 2 … 3
Best results in the field 6 … 10 3
Aspect ratios for differentprocesses at present day
29
R2R waveguide sensors
Sensor roll Sensor chip Sensor waveguide
Sensor roll length is some hundreds of metersSensor chip dimensions are in centimeters mostly due to robust samplehandling-> one roll can contain tens of thousands of sensor chipsTypical waveguide width is 1…3 µmSensor elements are functionalized/passivated in post-process
303005/05/2014
R2R SERS sensor chip development inPhotosens consortium project
Nanoimprinted roll of substrateshowing continuous SERS array
Nanoimprinted roll of substrateshowing and cut out 96 wellplate (gold coated)
SPIE Next Generation Spectroscopic Technologies 2014
3105/05/2014 31
Enabling technology: Silicon photonics
Photonic integrated circuits on SOI wafersVTT has developed a unique µm-scale SOI waveguide platformDense integration and low-cost volume productionLow propagation losses (0.1 dB/cm)Small polarisation dependencySingle-mode operation over an ultra-wide wavelength range
Click to edit Master title style
Click to edit Master text stylesSecond level
Third levelFourth level
Fifth level
3205/05/2014 32
Microspectrometers with silicon photonics ?
Emerging technology for microspectrometers in the futureMultiple wavelength filters in a single circuitWideband & narrowband filtering combinedFilter tunability, switching and modulationLight sources and detectors can be hybridintegrated on SOI chips
SPIE Next Generation Spectroscopic Technologies 2014
Thank you for your attention !