New Small Spectrometer Concepts Covering the Ultraviolet to the Mid-Infrared

Transcription

1 New Small Spectrometer Concepts Covering the Ultraviolet to the Mid-Infrared John Coates Coates Consulting Process Spectroscopy IFPAC-2014 Thursday PM VIII

2 New Approaches in Spectroscopic Measurements: Example, Spectral Sensors Trends away from traditional thinking Traditional instruments are large and expensive Move towards smaller systems Trend to point of measurement or sample production, process and environmental Smaller instruments favor in distributed measurement schemes and remote monitoring Recent trends towards portable and handheld Current trends a good fit with enabling technologies such as miniaturization, MEMS, handheld computing and wireless The GameChangers spectral sensors and detectors fully integrated devices based on solid state components

3 Key Enabling Technologies for Miniaturization and Low Cost Thin film filter technologies Bandpass filters covering from deep UV (220nm) to the mid-ir (15m, 15,000nm) Patterned filters produced by microlithography techniques Linear variable filters currently from the long UV (350nm) to the mid-ir (15m, 15,000nm) MEMS as applied to spectroscopy Detector arrays in the mid-ir FTIR Engine Lasers and LEDs Broad range of LEDs from UV (250nm) to NIR (1450nm) and out to the upper mid-ir (around 3m) Laser Diodes (NIR) and QCL Mid-IR lasers Fiber optics Materials available covering from far UV to mid-ir Fiber faceplates for optical interfacing and geometry conversion

4 New Technologies: Small Spectrometers and Photometers UV-Visible Light Photometric Sensors Miniature UV-Vis-NIR Sensor New Near-Infrared Small Spectrometers DLP Spectrometer Concepts Mid-Infrared Photometric Gas Sensors Mid-IR Photometers includes handheld diagnostic systems Multicomponent gas analyzers ATR and Transmission IR spectrometers Multicomponent fluid analyzers

5 Integrated Chip-Scale Micro-Spectrometer Platform (Designed for Customization) Miniaturized solid state spectrometers An integration of three custom components (detector, filter and collimation optic) to provide a functioning optical spectrometer head as a single monolithic component Designed to be integrated with electronics micro or ASIC Spectral ranges: the visible, the SW-NIR, and the NIR Device is conceived as a single component that can be integrated into a measurement flow system or stand-alone in a handheld device Applications include most automotive fluids, including coolant, DEF, lubricants, etc.. Example application is for fuel performance characteristics gasoline and diesel Chemicals and petrochemicals Pharmaceutical dosage forms and raw materials Food products, etc

6 Integrated Chip-Scale Micro-Spectrometer: Full Spectral Sensor Visible Example automotive engine coolants

7 Integrated Chip-Scale Micro-Spectrometer: Full Spectral Sensor NIR Solvents Breadboard prototype Initial data Automotive Water Coolant DEF

8 DLP is a MEMS Device DLP chip or DMD Array of micromirrors Array of micromirrors..that digitally switch (plus or minus) to steer light. DLP is a fast, efficient and reliable spatial light modulator (SLM)

9 DLP used as a Spectral Measurement System When illuminating the DLP/DMD with dispersed light, the micromirror array can function as a spectrometer In this configuration, DLP/DMD pixel-columns select the wavelength The spectrum can be scanned by sweeping the DLP array The output can be tuned in terms of line width and intensity Combined response can be used to flatten the energy background 2. Turn on columns to select wavelength, number of pixels to select intensity

10 Example Czerny Turner Design using a DMD

11 Proof-of-concept/Evaluation Prototype ROBUST PORTABLE DESIGNS PROGRAM- MABLE SPECTRUM ACQUISITION MODES Flexible platform Sampling and operation

12 TI DLP LightCrafter Miniature Projector: Spectrometer Attachment LightCrafter Engine Alternative approach to the DLP Platform lower cost LightCrafter Engine 10mm Sample Cell Holder

13 MEMS Sensor Platform Technology for Gases and Vapors MEMS Filter based infrared sensor and spectral engines Custom-designed engines featuring pulsed IR sources and unique MEMS detector-filter combinations Multiple component monitoring with 4 to 16 channels Pathlengths from 5mm to 1meter Example gases and vapors Natural gas composition for Methane Number and Calorific Value Combustion gases CO 2, SOx, NOx, NH 3, etc Environmental air quality In-line process applications Refrigerants

14 Ambient Air Gas Sensors: 4 to 16 channels The geometry of the measurement system defines the sensor sensitivity version shown left monitors %levels Integrated system with sample transfer A different configuration can monitor ppm levels shown below High SNR electronics enables measurements as low as 1 to 20ppm, dependent on the gases

15 Example Applications of Ambient Air Monitors Ambient air monitor includes an integrated fan driven airflow system Designed to operate like a nose Can characterize vapors and gases Can monitor build of vapors from spills and leaks

16 Original Breadboard Concept Stand-alone Mid-IR LVF-Based ATR Analyzer Developed in 2011 Features MEMSbased IR detector array First in a new series analyzers Designed for embedded, benchtop and handheld applications Configurations: ATR Transmission

17 Example Handheld Integrated ATR System (Sisol) Example applications: Chemical identification materials in unlabeled containers Common industrial solvents Process and quality control production of formulated products Automotive fluids fuels, oils, etc. Automotive applications Fuels fuel blends, green fuels, etc. Quantitative measurement of fuels Lubricants and synthetics Water soluble fluids and water content

18 Sisol: Aromatic and Aliphatic Hydrocarbons: Related to Fuel Components Differentiation of hydrocarbons used in fuels and solvent Simple aliphatics key components for fuels such as gasoline comparison of linear hydrocarbons (n-hexane) and branched chain hydrocarbons (2,2,4-trimethylpentane, isooctane) Differentiation with aromatics examples, toluene and xylene

19 Sisol: Automotive Green Fuel Blends Example green fuels Gasoline-alcohol blends Example shown (left) for regular gasoline, no added alcohol (blue) and regular plus standard addition of alcohol, NE blend, ~10% Ethanol (red) Example green fuels Diesel-biodiesel blends Example shown (right) for standard diesel with progressive addition of biodiesel from 10% (B10) to pure biodiesel (100%)

20 Sisol: Common Solvents and Chemical Functionality Beyond automotive A common application of IR spectroscopy is for the identification of compounds and differentiation of different chemical functionality Examples shown for alcohols, ketones and aromatic compounds Materials can be rapidly identified and characterized

21 MEMS Array-Based IR Analyzer Designed for in-line process applications High-pressure liquid transmission cell shown

22 New Technologies Simple Photometric Engines & Applications UV-Visible Light Photometric Sensors Color-based measurements Fluorescence methods Near-Infrared Photometric Sensors Solvents, oil and petroleum products Reaction monitoring known targets Liquid products consumer products Powders and solid substrates Mid-Infrared Photometric Sensors Mid-IR Photometer includes handheld diagnostic systems Multicomponent gas analyzers Multicomponent fluid analyzers

23 Keeping Spectroscopy Small, Simple and Low Cost! Keeping Spectroscopy Small Palm-sized Analyzers In-line sensors Embedded spectrometers Spectral detectors Spectroscopy Applications UV-Visible Spectral Detector Near-Infrared Spectral Detector Mid-IR Spectral Detector Gas and Liquids (fixed wavelengths) Full spectra - MEMS-based technology Cost effective solutions UV-Vis target cost ~$250 (Volume) SW-NIR target cost ~$250 (Volume) LW-NIR ~$1500 (Volume) to $5000 IR from $5000 (Low Volume)