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Luminescence thermometry for in situ temperature measurements in microfluidic devices

LAB ON A CHIP 2019年第7期19卷 1236-1246页

作者： Geitenbeek, Robin G. Vollenbroek, Jeroen C. Weijgertze, Hannah M. H. Tregouet, Corentin B. M. Nieuwelink, Anne-Eva Kennedy, Chris L. Weckhuysen, Bert M. Lohse, Detlef van Blaaderen, Alfons van den Berg, Albert Odijk, Mathieu Meijerink, Andries Univ Utrecht Debye Inst Nanomat Sci Condensed Matter & Interfaces Princetonpl 1 NL-3584 CC Utrecht Netherlands Univ Twente MESA Inst Nanotechnol Lab On A Chip Grp BIOS POB 217 Enschede Netherlands Univ Twente MESA Inst Nanotechnol Phys Fluids POB 217 Enschede Netherlands Univ Utrecht Debye Inst Nanomat Sci Inorgan Chem & Catalysis Princetonpl 1 NL-3584 CC Utrecht Netherlands Univ Utrecht Debye Inst Nanomat Sci Soft Condensed Matter Princetonpl 1 NL-3584 CC Utrecht Netherlands

temperature control for lab-on-a-chip devices has resulted in the broad applicability of microfluidics to, e.g., polymerase chain reaction (PCR), temperature gradient focusing for electrophoresis, and colloidal particle synthesis. However, currently temperature sensors on microfluidic chips either probe temperatures outside the channel (resistance temperature detector, RTD) or are limited in both the temperature range and sensitivity in the case of organic dyes. In this work, we introduce ratiometric bandshape luminescence thermometry in which thermally coupled levels of Er3+ in NaYF4 nanoparticles are used as a promising method for in situ temperature mapping in microfluidic systems. The results, obtained with three types of microfluidic devices, demonstrate that temperature can be monitored inside a microfluidic channel accurately (0.34 degrees C) up to at least 120 degrees C with a spot size of ca. 1 mm using simple fiber optics. Higher spatial resolution can be realized by combining luminescence thermometry with confocal microscopy, resulting in a spot size of ca. 9 m. Further improvement is anticipated to enhance the spatial resolution and allow for 3D temperature profiling.

关键词： Spatial resolution temperature control Electrophoresis Microfluidics spot size confocal microscopy temperature Fiber optics Lab-On-A-Chip devices resistance thermometers Thermometry temperature sensor device component Microfluidic devices

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Upconversion and thermometric applications of Er³⁺-doped Li:TeO₂ glass

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APPLIED PHYSICS B-LASERS AND OPTICS 2006年第2期82卷 289-294页

作者： Singh, AK Rai, SB Rai, DK Singh, VB Banaras Hindu Univ Dept Phys Laser & Spect Lab Varanasi 221005 Uttar Pradesh India PG Coll Dept Phys Varanasi Uttar Pradesh India

Near-infrared (NIR) excitation of Er3+-doped lithium-modified tellurite (Li:TeO2) glass results in anti-Stokes fluorescent emissions near 380 nm, 530 nm, 551 nm and 654 nm in addition to NIR Stokes emission. The anti-Stokes emissions are ascribed to transitions from the excited (4)G(11/2), S-4(3/2)(H-2(11/2)) and F-4(9/2) levels in Er3+. The excitation involves three and two incident photons. 532-nm excitation of this glass also leads to similar emissions. The mechanisms involved in these processes are discussed and the upconversion efficiency is calculated. The temperature dependence of the upconversion process has also been investigated. It is found that Er3+-doped tellurite glass can be used as a temperature sensor in the range 300-530 K.

关键词： FLUOROINDATE GLASSES temperature sensor SPECTROSCOPIC PROPERTIES OPTICAL SPECTROSCOPY TELLURITE GLASSES FLUORESCENCE IONS BLUE ER3+ WAVE Fluorescence tellurite Tellurite glasses Upconversion OPTICAL SPECTROSCOPY waveforms Ions temperature sensor device component

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Thermal optimization on micromachined convective accelerometer

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HEAT AND MASS TRANSFER 2002年第7-8期38卷 705-712页

作者： Luo, XB Li, ZX Guo, ZY Yang, YJ Tsing Hua Univ Dept Engn Mech Beijing 100084 Peoples R China Hebei Semicond Res Inst Shijiazhuang 050051 Peoples R China

A kind of micromachined convective accelerometer without solid proof mass is numerically and experimentally studied in this paper. The accelerometer consists of a micro heater and two temperature sensors which measure the temperature difference between two symmetrical positions on both sides of the micro heater. The temperature difference is caused by free convection due to acceleration. Thermal optimization on the accelerometer is conducted based on numerical simulation. Three important indexes of the accelerometer, linearity, sensitivity and frequency response are discussed respectively. The results show that linearity relates with the non-dimensional number Gr, only when Gr is in the range from 10(-2) to 10(3), good linearity can be achieved. The optimum sensor position for high sensitivity and good linearity is near at x/D = 0.3. An increase of heating power or cavity size leads to an increase in the sensitivity. The working media that has small density rho and large thermal diffusivity alpha is favorable for fast frequency response, the one having large density rho and small kinematic viscosity v will be advantageous for high sensitivity. Experimental tests prove that the optimized convective accelerometer has good linearity, high sensitivity and preferable frequency response.

关键词： accelerometers cavity dimension FREE CONVECTION temperature gradients temperature sensor device component convection frequency response Linearity heating power

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Solution of inverse heat conduction problems using control volume approach

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INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 1999年第6期42卷 1123-1140页

作者： Taler, J Zima, W Cracow Univ Technol Inst Proc & Power Engn PL-31155 Krakow Poland

A new method for solving multidimensional inverse heal conduction problems is presented. Using control volume methods, the partial heat conduction equation is replaced by a system of ordinary differential equations in time, which are then solved sequentially. The procedure is started at a spatial node where temperature sensor is located and sequentially marches through space to the surface node. The accuracy of the method was demonstrated by comparison of the calculated surface heat flux and temperature with the known exact solution. Two numerical experiments, one- and two-dimensional inverse heat conduction problems, are solved to illustrate the effectiveness. computational efficiency and good accuracy of the presented method. In the third example, the inverse formulation is applied to a set of experimental data. The method can easily be extended to three-dimensional cases. (C) 1998 Elsevier Science Ltd. All rights reserved.

关键词： Solution Standing Orders Conductive heat transfer new methods Inverse Volume CONTROL VOLUME METHOD Marches Italy temperature sensor device component

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A semi-numerical method for solving inverse heat conduction problems

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HEAT AND MASS TRANSFER 1996年第3期31卷 105-111页

作者： Taler, J Cracow University of Technology Institute for Process and Power Engineering ul. Warszawska 24 PL-31-155 Krakow Poland

A semi-numerical method is presented for solving the inverse heat conduction problems in homogeneous and composite bodies. The presented solution does not require both the initial temperature distribution in the body and the whole temperature-time history at the temperature sensor locations. Sample calculations confirm that this approach produces stable and accurate results for both exact and noisy data. The extension of the method presented to two or three dimensions is straightforward.

关键词： Inverse Body Exact temperature distribution initial temperature temperature sensor device component Numerical methods noisy data Conductive heat transfer Heterogeneous

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Differential six-port reflectometer for determining dry rubber content of latex

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IET MICROWAVES ANTENNAS & PROPAGATION 2015年第8期9卷 847-851页

作者： Julrat, Sakol Chongcheawchamnan, Mitchai Robertson, Ian D. Segate Technol Thailand Teparak Smutprakarn Thailand Prince Songkla Univ Dept Elect Engn Hat Yai Songkhla Thailand Univ Leeds Inst Microwaves & Photon Leeds W Yorkshire England

This study presents the application of a differential six-port reflectometer to the design of a portable system for measurement of the dry rubber content (DRC) of latex. The proposed DRC measurement system consists of a 1 GHz reflectometer used with an open-ended coaxial-probe sensor, a temperature sensor, a display and a microcontroller. The complex permittivity and temperature of the rubber latex are measured, and a temperature-dependent model for DRC determination based on a dielectric mixture theory is used. The reflectometer performance is verified by comparing the measured complex permittivity with the results obtained from a commercial dielectric measurement system. Finally, the accuracy of the DRC measurement system is assessed by comparing the measured DRCs from different latex samples over the range of 10-40 degrees C with the standard oven-drying method.

关键词： Complex permittivity measurement system Latex portable system temperature sensor device component rubbers drought rubber latex

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A DEWPOINT temperature sensor-BASED ON ND3+-DOPED FIBER FLUORESCENCE

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IEEE PHOTONICS TECHNOLOGY LETTERS 1995年第10期7卷 1198-1200页

作者： KARDOS, VJ SONEK, GJ UNIV CALIF IRVINE BECKMAN LASER INST & MED CLINIRVINECA 92717

The design and performance characteristics of a portable dewpoint temperature sensor based on the fluorescence emission derived from an 830-nm diode-pumped, single-mode Nd3+-doped fiber, are reported. Dewpoint temperature is measured using an optical reflectance technique at the fiber-fluorescence emission wavelength of 950 mn, where water has a local absorption maximum and substrate reflectivity exceeds 98%. The sensor exhibits a signal-to-noise ratio (S/N) of 22 dB and a dewpoint precision of +/- 0.2 degrees C at a fluorescence power of 5 mu W.

关键词： Fiber performance characteristics Dew Point temperature temperature sensor device component Fluorescence

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Optical Thermometry through Green Upconversion Emissions in Er³⁺/Yb³⁺-Codoped CaWO₄ Phosphor

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APPLIED PHYSICS EXPRESS 2012年第7期5卷 72201.1-72201.3页

作者： Xu, Wei Gao, Xiaoyang Zheng, Longjiang Wang, Peng Zhang, Zhiguo Cao, Wenwu Harbin Inst Technol Condensed Mater Sci & Technol Inst Harbin 150001 Peoples R China Yanshan Univ Inst Elect Engn Qinhuangdao 66004 Peoples R China Penn State Univ Mat Res Inst University Pk PA 16802 USA

Under 980 nm excitation, the temperature-dependent green upconversion emissions from Er3+/Yb3+-codoped CaWO4 phosphor were studied at temperatures from 294 to 923 K. By using the fluorescence intensity ratio technique, the maximum sensitivity for temperature measurement achieved here is approximately 0.0092 K-1, which is much higher than previously reported temperature sensors based on the fluorescence of Er3+ ions in other host materials. With the efficient upconversion fluorescence, the Er3+/Yb3+-codoped CaWO4 is a very promising candidate for optical high-temperature sensors with high sensitivity and good accuracy. (c) 2012 The Japan Society of Applied Physics

关键词： peak response temperature measurement Fluorescence optical Upconversion green host material temperature sensor device component Thermometry candidate species

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Ultrahigh-sensitivity fiber-optic strain and temperature sensor

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OPTICS LETTERS 1998年第3期23卷 222-224页

作者： Friebele, EJ Putnam, MA Patrick, HJ Kersey, AD Greenblatt, AS Ruthven, GP Krim, MH Gottschalck, KS USN Res Lab Div Opt Sci Washington DC 20375 USA Hughes Danbury Opt Syst Danbury CT 06810 USA

We report ultrahigh-sensitivity static strain sensing (noise equivalent strain less than or equal to 1.5 n epsilon rms) by two fiber etalon cavities made from silica and fluoride fibers. The anomalous thermo-optic coefficient of fluoride glass fibers allows for determination of thermal and laser drift. This sensor is also capable of simultaneous strain and temperature measurement, with errors in strain and temperature of 6.4% and 0.68%, respectively.

关键词： Fiber Thermal temperature sensor device component Laser static strain fluoride glasses noise equivalent Optical Fibers Less than or equal to temperature measurement

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The mean temperature field of a buoyancy-induced boundary layer adjacent to a vertical plate immersed in a stratified medium

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INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 1998年第14期41卷 2125-2130页

作者： Tanny, J Cohen, J Technion Israel Inst Technol Fac Aerosp Engn IL-32000 Haifa Israel Ctr Technol Educ Holon IL-58102 Holon Israel

The mean temperature field of a buoyancy-induced boundary layer adjacent to an isothermal vertical flat plate immersed in a linear ambient thermal stratification is investigated experimentally. Experiments are carried out in an apparatus, consisting of a square perspex aquarium and a heated plate assembly. Mean temperature measurements are conducted using constant current fiber-film temperature sensors. The temperature profiles for unstratified and stratified media are compared with corresponding theoretical similarity solutions and good agreement is obtained. Accordingly, for the case in which the environment is thermally stratified, the mean temperature profiles possess a region of temperature deficit (negative dimensionless temperature) and the thickness of the boundary layer is approximately independent of the streamwise coordinate. Measurements of the local heat transfer are in good agreement with corresponding theoretical predictions. (C) 1998 Elsevier Science Ltd. All rights reserved.

关键词： Flow Environment plate Vital Signs Bone Plate temperature profiles temperature fields PLATES IMMERSING temperature boundary layer Flow Neighbor local heat transfer Similarity solutions temperature sensor device component Environments

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