Temperature Sensitive Element Research Articles

MoS2high temperature sensitive element with a single Si3N4protective layer.

Temperature sensors find extensive applications in industrial production, defense, and military sectors. However, conventional temperature sensors are limited to operating temperatures below 200°C and are unsuitable for detecting extremely high temperatures. In this paper, a method for thermal protection of molybdenum disulfide (MoS2) films is proposed and a MoS2 high temperature sensor is prepared. By depositing a monolayer of Si3N4 onto MoS2, not only is the issue of high-temperature oxidation effectively addressed, but also the contamination by impurities that could potentially compromise the performance of MoS2 is prevented. Moreover, the width of the Schottky barrier of metal/MoS2 is reduced by using PECVD deposition of 400 nm Si3N4 to form an ohmic contact, which improves the electrical performance of the device by three orders of magnitude. The sensor exhibits a positive temperature coefficient measurement range of 25 to 550°C, with a maximum temperature coefficient of resistance (TCR) of 0.32%·°C-1. The thermal protection method proposed in this paper provides a new idea for the fabrication of high-temperature sensors, which is expected to be applied in the high-temperature field.&#xD.

Laser Powder Bed Fused Parts made of SS316 with Embedded Fibre Optic Sensors for Temperature Monitoring up to 1000°C

A smart metal component with an integrated high temperature sensing capability is presented. The metallic structure in SS316 is manufactured by an additive layer process based on laser powder bed fusion (LPBF). The sensor, a temperature sensitive in-fiber Fabry-Perot element, is encapsulated in a capillary and embedded into the structure during the LPBF build process. It is demonstrated that the sensor can measure the temperature inside the metal up to 1000°C with accuracy better than 10°C for extended periods far in excess of 300 h.

Investigations of temperature sensor embedded into PCB

PurposeThe purpose of this study is to design and fabricate a simple passive sensor circuitry embedded into a printed circuit board (PCB) and then to examine its properties.Design/methodology/approachA passive sensor transponder integrated circuit (IC) working in the high frequency (HF) 13.56 MHz frequency band was selected for this study. A loop antenna was designed to make the reported sensor circuitry readable. Next, the sensor circuitry was fabricated and embedded into a PCB with the proposed technologies. Finally, properties of the embedded structures were examined as well-functional parameters of the sensor circuitries.FindingsThe described investigation results confirmed that the proposed technologies using an epoxy resin or standard materials used for PCB’s production allowed to successfully produce sensors embedded into PCBs. This technology did not have a negative significant impact either on quality of solder joints of the assembled transponder IC or on functional properties of the embedded sensor. Apart from the identification data, the reported sensor can provide information about a selected property of its environment, e.g. temperature when its internal temperature sensitive element is used or other factors with the use of external sensitive elements, such as humidity.Research limitations/implicationsIt is planned to carry on the reported investigations to examine other types of sensor circuitries capable of indicating e.g. humidity level and to evaluate influence of the proposed technology on their functional properties.Practical implicationsThe reported sensor circuitries can be successfully used in electronic industry in internet of things systems not only to identify monitored electronic devices, but also to control selected parameters of external environment. This creates opportunity to detect device malfunction by detecting local temperature growth or to analyze its environment, which might allow to predict failure of controlled products using radio waves. This advantage seems to be extremely beneficial for applications, such as space, aviation or military, in which embedded sensor systems may lead to enhancing reliability of electronic devices by reacting on occurred failures in a more efficient way.Originality/valueThis study demonstrates valuable information for engineers conducting research on sensor components embedded into PCBs. The reported technologies are quite simple and cost-effective because of the use of standard materials known for PCB’s production or an epoxy resin which could be treated as an additional encapsulant material enhancing mechanical properties of the embedded sensor transponder IC.

Thin film resistance thermometer with simple package for cryogenic application

In this paper, we proposed a novel simple package based on micro-machining for thin-film cryogenic temperature sensors. The substrate with temperature sensitive element fabricated by micro-machining process, directly used as the package substrate. Then, the silicon cover soldered on the substrate, providing vacuum encapsulation with high air tightness. Subsequently, we researched the reliability of the package by leak rate detection, shear force test and scanning electron microscope. Lastly, the temperature response curves, measurement fluctuation, thermal response time and short-term stability of the thermometers had been researched. Compared to the traditional package, the simple package simplified manufacturing process, reduced cost. Furthermore, the temperature sensitive element directly deposited on the package substrate, reduced sensor mass and improved thermal response speed.

Compensation of Environmental Influences on Sensorized-Forceps for Practical Surgical Tasks

For more secure and delicate robotic surgery, force sensing ability is essential but it has still not been used in actual robot surgery. This is because the environmental factors that occur during actual operation affect the sensor and the sensor cannot give reliable force information. In this letter, we aim to develop reliable sensorized-forceps that can be used in practical surgical tasks by compensating environmental influences. The environmental factors affecting the sensor were analyzed. Humidity, temperature, and high voltage were considered as main factors. At first, to compensate the humidity influences, the humidity sensing capability was integrated in the sensorized-forceps and humidity compensation algorithm is applied. Second, to eliminate the temperature-sensitive element, ac shield is applied to the signal processing board. Finally, for cutting off electric conduction, entire surface of forceps is covered by an oxide layer. To verify the proposed solutions, revised sensorized-forceps are installed in surgical robot platform and ex vivo experiments with electro-cautery task were conducted.

Design guidelines of laser reduced graphene oxide conformal thermistor for IoT applications

This work presents a complete temperature sensing solution based on a conformal laser-reduced graphene-oxide temperature transducer acting as thermistor. The process to implement the temperature-sensitive element is described in detail; from the raw material to the optimum laser scribing conditions used to define the resistive component. The final transducer is fabricated on a flexible plastic substrate and can be attached to any surface as a conformal patch. To provide a full demonstrator of the potential of this technology, the thermistor is integrated in an IoT sensing platform with wireless data transmission capability using a reconfigurable ultra-low power System-on-Chip.

Development of a thermosensitive molecularly imprinted polymer resonance light scattering sensor for rapid and highly selective detection of hepatitis A virus in vitro

In this study, a thermosensitive imprinted polymer coating SiO2 was developed for a resonance light scattering (RLS) thermosensitive virus-affinity sensor, which exhibited high selectivity for virus monitoring. In this sensor, N-isopropylacrylamide was a temperature-sensitive element. The recognition performance of the nanosensor for viruses was regulated by temperature control for the specific capture of the target virus at 40°C, resulting in the increase of RLS intensity and its release at 20°C. Moreover, the RLS intensity of the nanosensor significantly increased within 30min. Accordingly, a very good detection limit of 1.1pmolL−1 was obtained. The nanosensor was successfully used to detect the additional hepatitis A virus from a dilution of human serum, and recoveries in the range of 90.8% to 108.3% were attained at three spiking levels of viruses. Overall, this study addressed the problems of high nonspecific adsorption and long duration of detection process. Furthermore, a facile, rapid, and efficient tool for virus detection was provided.

Thermo-sensitive imprinted polymer embedded carbon dots using epitope approach

A new type of thermo-sensitive receptor carbon dots/SiO2/molecularly imprinted polymer (CDs/SiO2/MIP) was prepared by surface imprinting procedure and the epitope approach. The synthetic CDs/SiO2/MIP was able to selectively capture target protein with fluorescence quenching via the special interaction between them and the recognition cavities. The receptor exhibited the linear fluorescence quenching to cytochrome c (cyt c) in the range of 0.1–40μM, and the detection limit was 89nM. The precision for five replicate detection of cyt c at 20μM was 3.11%. Moreover, the receptor owned the temperature-sensitive element that allowed for swelling and shrinking in response to temperature changes to realize recognition of the target cytochrome c. The proposed strategy revealed the feasibility of fabrication of a thermo-sensitive imprinted polymer based on CDs and surface imprinting procedure and the epitope approach.

Modeling of Temperature Effects on Micromachined Silicon Thermal Wind Sensors

A 2-D micromachined silicon thermal wind sensor measures wind speed and direction by monitoring temperature differences induced by an airflow that passes along the substrate surface. When ambient temperature changes, however, the temperature drift of the sensor will lead to incorrect output values. By examining the thermophysical properties of the airflow, substrate, and temperature sensitive element, this paper has developed a closed-form semi-empirical model to understand the physical origins of temperature drift in the 2-D micromachined silicon thermal wind sensor. Using the model, the temperature drift can easily be compensated by directly extracting two empirical parameters from the uncompensated sensor output. Experiments presented here show that the temperature compensated sensor is working well in a temperature range between −20 °C and 40 °C with the relative error being less than ±3.5%. [2015-0121]

Molecularly imprinted hydrogels for application in aqueous environment

Molecularly imprinted thermoresponsive hydrogels for dopamine recognition were synthesized using N-isopropylacrylamide as the temperature-sensitive element, methacrylic acid or itaconic acid as functional monomer and N,N’-methylenebisacrylamide or ethylene glycol dimethacrylate as crosslinking agent. The stoichiometry of the template–functional monomer prepolymerization complexes was determined by 1H NMR experiments according to the Job method of continuous variation as well as signal line width analysis. It was found that dopamine hydrochloride forms complexes with methacrylic acid and itaconic acid with 1:3 and 2:3 template to functional monomer stoichiometry, respectively. Hydrogels composed of itaconic acid and with appropriate template content revealed the highest efficiency of imprinting process and relatively high selectivity of dopamine hydrochloride rebinding in water near the phase transition temperature.

Temperature measurement of high-density winding coils of electromagnets

In this study, the temperature of high-density winding coils of electromagnets is measured without using any temperature measurement probe. In fact, the probe cannot get access to the interior of the coil. Infrared radiometry can measure only the coil surface temperature which can be very different from the interior temperature. In the present measurement technique, the copper winding wire itself is used as the temperature-sensitive element. The current against voltage (I–V) of the coil is first measured. The electrical resistance of the coil is then obtained and plotted against dissipation power. Using the thermal coefficient of the electrical conductivity of copper at ambient temperature (20°C), the coil temperature is deduced and plotted against dissipation power. The resulting temperature is the temperature along the wire averaged over the entire wire length. This is the average interior temperature rather than surface temperature. The case temperature is measured by a precision thermometer. The difference between coil temperature and case temperature is calculated and divided by dissipation power to attain the thermal resistance from the coil to the case. For the electromagnet studied, the thermal resistance is 1.1°C/W. Electromagnets are components that are used in numerous electrical machines and electronic products. Coil temperature measurement is of critical importance because the insulating coating of the winding wire has finite temperature ratings beyond which the coating may deteriorate and get damaged. By using the pulsed mode, the technique presented here can be implemented to measure the coil temperature even while the electromagnets are in operating conditions. It should be valuable to the electricity and motor industries.

Wireless Temperature Sensing with BST-Based Chipless Transponder Utilizing a Passive Phase Modulation Scheme

A passive wireless temperature sensor with identification capabilities based on a phase modulation scheme is discussed in this paper. The approach presented utilizes a pulse backscatter technique based on slow wave (metamaterial) transmission lines. The focus of the work are the material engineering for the temperature-sensitive element and the integration of this element into a passive phase modulation circuit and the entire sensor tag. The approach makes use of temperature-sensitive bariumstrontium-titanate thick film capacitances. The discussed principle has been experimentally verified with a prototype.

NEUTRON IRRADIATION EFFECTS IN PZ and PZT THIN FILMS†

ABSTRACT Neutron irradiation effects on highly oriented antiferroelectric PbZrO3 (PZ) and ferroelectric PbZr0.53Ti0.47O3 (PZT) thin films are investigated in view of their possible application as a temperature sensitive element in a new bolometer system for fusion devices like ITER. All investigated thin films were prepared by a sol-gel technique and by pulsed laser deposition (PLD) respectively. The dielectric properties were investigated in a frequency range from 1 to 250 kHz and at temperatures up to 400°C, prior to and after irradiation to a neutron fluence of 3 * 1022 m−2 (E > 0.1 MeV). After irradiation, the films were anneald in several steps up to 400°C in order to remove the radiation-induced defects. The results are discussed in terms of two kinds of radiation-induced defects, i.e. structural defects, such as oxygen-vacancies, and radiation-induced charges. We find that the antiferroelectric PZ heterostructures are radiation harder than the PZT films and that the structural order of the film as well as the interfaces play an important role. †Originally presented at 10th European Meeting on Ferroelectricity, Cambridge, UK, August 3-8, 2003.

Oxygen vacancy defects in antiferroelectric PbZrO3 thin film heterostructures after neutron irradiation

Neutron irradiation effects on highly oriented antiferroelectric PbZrO3 (PZ) thin films are investigated in view of their possible application as a temperature sensitive element in an alternative bolometer system for fusion devices such as the International Thermonuclear Experimental Reactor (ITER). All films were prepared by a sol-gel technique or by pulsed laser deposition (PLD). The dielectric properties were investigated in a frequency range from 1 to 250kHz and at temperatures up to 400°C, prior to and after irradiation to neutron fluences of 0.5×1022, 1×1022, 2×1022, and 3×1022m−2 (E>0.1MeV). After irradiation, the films were annealed in several steps up to 400°C in order to remove the radiation-induced defects. The results are discussed in terms of a phenomenological model of radiation effects in PZ films, which takes into account structural defects, such as oxygen vacancies, and radiation-induced charges. We find that the films are most sensitive to neutron irradiation in the vicinity of the phase transistion temperature Tc. In addition, the structural order of the films as well as the interfaces play an important role. We find that the PZ heterostructures prepared by PLD are radiation harder than the sol-gel films. The dielectric properties of the PLD films are more or less unaffected by neutron irradiation up to a fluence of 3×1022m−2 (E>0.1MeV).

Radiation-induced defects in antiferroelectric thin films

Radiation effects on highly oriented antiferroelectric (AFE) PbZrO 3 (PZ) films with a thickness of approximately 400 nm are investigated in view of their possible application as a temperature sensitive element in a new bolometer system for fusion devices like ITER. The films were prepared by pulsed laser deposition (PLD). The dielectric constant was measured in the frequency range from 1 to 250 kHz in a stepwise cooling mode (∼2 °C min −1) from 400 °C to room temperature before and after irradiation to a fast neutron fluence of 2×10 22 m −2 (E>0.1 MeV). After irradiation, the films were annealed in several steps up to ∼400 °C to remove the radiation-induced defects. The results are discussed in terms of two kinds of radiation effects, i.e. structural defects (oxygen vacancies) and radiation-induced charges, trapped at defect structures. The measurements show significant differences to sol–gel PZ thin films, which is mainly explained by the high quality of the PLD films.

DnaK-Sigma 32 Interaction Is Temperature-dependent: IMPLICATION FOR THE MECHANISM OF HEAT SHOCK RESPONSE

The heat shock response in bacteria is a complex phenomenon in which sigma 32 plays the central role. The DnaK/J chaperone system binds and promotes degradation of sigma 32 at lower temperatures. At heat shock temperatures, the DnaK/J-mediated degradation of sigma 32 is largely abolished by a mechanism, which is not yet fully understood. In this article we have shown that interaction of DnaK with sigma 32 is highly temperature-dependent. This interaction is completely abolished at 42 degrees C. To investigate the origin of such strong temperature dependence, we have monitored the structural changes that occur in the sigma 32 protein upon upshift of temperature and attempted to elucidate its functional roles. Upon a shift of temperature from 30 to 42 degrees C, the CD spectrum of sigma 32 becomes significantly more positive without significant change in either tryptophan fluorescence spectra or quenchability to external quenchers. 1,8-Anilinonaphthalene sulfonic acid binding at 42 degrees C is not significantly affected. The equilibrium guanidine hydrochloride denaturation of sigma 32 is biphasic. The first phase shifts to even lower guanidine hydrochloride concentrations at 42 degrees C, whereas the major phase remains largely unchanged. The sigma 32-core interaction remains unchanged as a function of temperature. This suggests that increased temperature destabilizes a structural element. We discuss the possible location of this temperature-sensitive structural element.

NOISE PROPERTIES OF HIGH TEMPERATURE SUPERCONDUCTING BOLOMETERS

The review describes the noise properties of the high temperature superconducting (HTS) bolometers developed for the applications in the optical electronic devices of infrared and submillimeter wave-lengths. The principle of high-Tc transition edge bolometer operation and bolometer noise theory are considered, taking into account the peculiarities of constant bias current and constant bias voltage modes. The published results of bolometer noise modeling are discussed. Various sources of the excess 1/f-noise in HTS films as temperature sensitive element for bolometer are reviewed, including the experimental data and modern noise models. Comparative analysis of noise characteristics of the most developed HTS bolometers for application (antenna-coupled microbolometers and bolometers based on silicon micromachining technology) is reported.

Seismoacoustic Hydrophysical Complex for Monitoring the Atmosphere–Hydrosphere–Lithosphere System

The seismoacoustic hydrophysical complex intended for investigation of the interaction of geospheres wave fields in a frequency range from 1 μHz to 1 Hz is described. The complex consists of a shore-based system of laser strain meters, laser nanobarograph, bottom station with a hydrophone and a temperature-sensitive element, weather station, and seismoacoustic radiator. The use of modern laser-interferometry methods provided a deformation sensitivity of ∼10–10 and an atmospheric-pressure sensitivity of 10 mPa.

Dielectric properties of reactor irradiated ferroelectric thin films

Radiation effects in highly oriented Pb1Zr0.53Ti0.47O3 (PZT), Pb0.94La0.06Zr0.65Ti0.35O3 (PLZT-6), and PbiZriO3 (PZ) ferroelectric (FE) and antiferroelectric (AF) thin films are investigated in view of their possible application as a temperature sensitive element in a new bolometer system for ITER (International Thermonuclear Experimental Reactor). The dielectric properties (i.e. hysteresis loops, dielectric constants) of the films were investigated in a frequency range from 20 to 105 Hz and at temperatures up to 450 °C, before and after neutron irradiation to a neutron fluence of 5×1021 m−2 (E<0.1 MeV). The dielectric constant was measured during cooling with 1.7 °Cmin−1. The dielectric properties of the films were assessed before and after annealing in several steps up to 490 °C to remove the radiation induced defects.

Fiber sensor for simultaneous measurement of voltage and temperature

We report a new configuration of the fiber-optic voltage sensor based on the Bi/sub 12/TiO/sub 20/ crystal, which allows simultaneous measurements of both voltage and temperature. In our scheme, a quarter-ware plate, being an inherent element of voltage sensor, serves simultaneously as a phase-shifting element and as a temperature sensitive element. The sensor operates at two wavelengths (633 and 976 nm). The sensor has a linear temperature characteristic within the range of 10/spl deg/C-70/spl deg/C, providing the accuracy of temperature measurements of 0.3/spl deg/C. As a voltage sensor, this device has a linear amplitude characteristic up to 1000 V/sub rms/ and the excellent temperature stability of 0.1% within the temperature range of 10/spl deg/C.-70/spl deg/C.