Temperature Sensor Research Articles

ZnO-Based Memristive Device for Temperature Sensing: Design, Modeling, and Performance Evaluation

This paper presents the design and modeling of a highly sensitive ZnO-based memristive temperature sensor, underpinned by the fundamental physics of memristive behavior. Utilizing a multi-physics simulation tool, the proposed model accurately maps temperature variation contours within the ZnO pyroelectric material, paving the way for its application in temperature sensing. An in-depth exploration of the sensor's electrical properties under varying temperature conditions reveals exceptional sensitivity (8.9 µV/K) and showcases the inherent non-volatile memory switching behavior of the memristor, making it ideally suited for dynamic applications. Moreover, this sensor operates inherently bias-free, functioning as a self-powered solution for emerging fields like the Internet of Things.

An automated AI-powered IoT algorithm with data processing and noise elimination for plant monitoring and actuating

This article aims to develop a novel Artificial Intelligence-powered Internet of Things (AI-powered IoT) system that can automatically monitor the conditions of the plant (crop) and apply the necessary action without human interaction. The system can remotely send a report on the plant conditions to the farmers through IoT, enabling them for tracking the healthiness of plants. Chili plant has been selected to test the proposed AI-powered IoT monitoring and actuating system as it is so sensitive to the soil moisture, weather changes and can be attacked by several types of diseases. The structure of the proposed system is passed through five main stages, namely, AI-powered IoT system design, prototype fabrication, signal and image processing, noise elimination and proposed system testing. The prototype for monitoring is equipped with multiple sensors, namely, soil moisture, carbon dioxide (CO2) detector, temperature, and camera sensors, which are utilized to continuously monitor the conditions of the plant. Several signal and image processing operations have been applied on the acquired sensors data to prepare them for further post-processing stage. In the post processing step, a new AI based noise elimination algorithm has been introduced to eliminate the noise in the images and take the right actions which are performed using actuators such as pumps, fans to make the necessary actions. The experimental results show that the prototype is functioning well with the proposed AI-powered IoT algorithm, where the water pump, exhausted fan and pesticide pump are actuated when the sensors detect a low moisture level, high CO2 concentration level, and video processing-based pests’ detection, respectively. The results also show that the algorithm is capable to detect the pests on the leaves with 75% successful rate.

Automation in Greenhouse using IoT

This work provides an IoT-based plant monitoring system for avoiding over-exploitation of resources, ensuring compact design with easy installation and the best environment for the plants to grow. This type of agricultural monitoring system provides environmental monitoring services that help the crop grow in good shape. The system offers the service of storing a database about the environment and soil information acquired from a wireless sensor network deployed in the planted area. Furthermore, it enables users to track environmental data regarding planted crops in real-time using any Internet-enabled device. Our project introduces automatic sunlight prevention and soil moisture control based on data received from the moisture and temperature sensors. The proposed work is implemented using a microcontroller, programmed accordingly to measure the temperature and moisture using respective sensors. It is well capable of controlling temperature by operating a fan, controlling a shade for blocking excess sunlight and controlling moisture by operating a watering device through a motor. The potential outcome of the project work can be used for greenhouse

Design and data processing for high-accuracy fluorescence lifetime of optical fiber temperature sensor using extended Kalman filter algorithm

Design and data processing for high-accuracy fluorescence lifetime of optical fiber temperature sensor using extended Kalman filter algorithm

Assessment of Albariño (<i>Vitis vinifera</i> sp.) plasticity to local climate in the Atlantic eastern coastal terroir of Uruguay

Plasticity is typically used in biology to describe the ability of an organism to adapt to changes in its environment. Within a viticulture production system under similar management practices, studying the plasticity of a specific cultivar under different local climatic conditions can enhance our understanding of the grape typicity and, consequently, the wine style of a region. This work aims to assess the performance of Albariño vines grown in different mesoclimates within the emerging wine region along Uruguay’s Atlantic coast. The study was conducted in a commercial vineyard in Garzón, Maldonado Department, a key location in this developing wine region. Temperature sensors were installed in each of the four Albariño plots, situated in two contrasting topographic positions relative to Atlantic Ocean exposure, to assess mesoclimate and the ocean’s influences on grapevine plasticity. Agronomic measurements were taken to assess the performance of Albariño under the local climatic conditions. The multivariate analysis of yield and berry composition variables with ocean exposure and seasonal climate has identified three key findings: 1) the Albariño cultivar has shown strong potential for cultivation in eastern Uruguay due to its favourable agronomic and oenological performance, 2) vineyard ocean exposure has a greater effect on berry composition at harvest than on yield, contributing 70.7 % and 63.4 % of the total variability, respectively as observed from the Principal Component Analysis, 3) the correlations between berry composition and ocean exposure are stronger under warmer and drier conditions. Understanding the plasticity of Albariño under different local climatic conditions is valuable for sustainable production systems, provided both production and high quality are maintained. This study highlights the importance of selecting appropriate cultivars and understanding the local climate for the future success of vineyards.

Highly sensitive liquid level and temperature sensors based on all-fiber intermodal interferometers

Abstract Fiber optic-based precise measurements of liquid level and temperature are crucial for remote controlling in pharmaceutics, chemistry, and bromatology. Thus, it is essential to monitor liquid level and temperature simultaneously. In this paper, we propose all-fiber intermodal interferometers for highly sensitive liquid level and temperature measurements. We fabricated two different structures of single mode fiber-no core fiber-single mode fiber (SMF-NCF-SMF). One of them was used to measure the liquid level when the liquid soaked the NCF, and the other one was further coated with PDMS thermal-optic material and utilized to detect temperature. The measurement sensitivity of liquid level was 580 pm/mm within the range of 0-20 mm, while that of temperature was 1 nm/°C within the range of 28-51°C. A matrix was finally obtained by demodulating the measurements of liquid level and temperature. The proposed liquid level and temperature sensors, exhibiting the merits of high sensitivity, easy fabrication, and low cost, could be a candidate for precise and remote monitoring of liquid levels.

Environment-tolerant, inherently conductive and self-adhesive gelatin-based supramolecular eutectogel for flexible sensor

Although hydrogels have attracted increasing attention in the stretchable devices, the low adhesion properties and poor environmental adaptation still seriously restrict their development and application. Herein, we focused on the interaction between polymer networks with disperse media and their resultant influence on gel performance, and constructed self-adhesive and environment-tolerant gelatin/polyacrylamide supramolecular-polymer double-network (Gelatin/PAM SP-DN) eutectogels using multiple supramolecular interactions between natural macromolecule and well-designed deep eutectic solvent (DES). The dual networks of Gelatin/PAM SP-DN eutectogels produced significant supramolecular forces with DES, including hydrogen bonding and electrostatic interaction, contributing to enhance the energy dissipation capacity. Additionally, the Gelatin-PAM SP-DN eutectogels were more prone to generate strong bonding force to various substrates, showcasing both in-situ and ex-situ adhesion performance, and even being used for wet and underwater adhesion. The eutectogels revealed excellent environmental tolerance to maintain excellent mechanical flexibility, conductivity and adhesion at high and low temperatures, ensuring the constructed sensor to sensitively and reliably perceive strain, pressure and human motions over a wide temperature range. Also, the eutectogel demonstrated great potential as a temperature sensor. This work opens up a new horizon in the design of multifunctional and environment-tolerant natural macromolecule-based gel materials for flexible electronics, human-machine interaction and health diagnosis.

Multi-layered morphing soft structure with high-performance embedded electrothermal artificial muscles along with touch and temperature sensors

Abstract In this paper, we present a novel multilayered morphing structure, having similar topology resembling the structures found in nature to grasp delicate objects effectively as well as sense contact force and temperature. The structure consists of two actuation layers, two U-shaped cooling channel layers, piezoelectric based touch sensors and temperature sensors. Employing shape memory alloy (SMA) spring actuators for bending and twisted and coiled polymer fishing line with nichrome (TCPFL NMC) artificial muscles for antagonistic return, the soft silicone-based composite skin exhibits unique capabilities of large bidirectional movement, avoid rigid passive springs for return motion, soft grasping, safe interaction with humans, and ease fabrication. The SMA (0.38 mm wire diameter) serves as relatively fast actuating muscle and the TCPFL NMC (0.8 mm fiber diameter) as a slow actuating (considering mainly heating cycle), which was programmed/designed to mimic the fast and slow twitching muscles found in nature. Bending and return operations of skin samples of length 100 mm and thickness of 9 mm, with three different widths 20 mm, 25 mm, 30 mm, were experimentally studied. The 25 mm wide multilayered soft skin demonstrated cyclic actuation with a maximum bending angle of ∼70°, which was attributed due to the active cooling. The fluidic channels for active cooling were fabricated using 3D printed PVA tubes, casting within the silicone in a mold and subsequently dissolving in a circulating water. The study also included the integration and voltage response of mini-piezodisk sensor PIC255 having a diameter of 2 mm and thickness of 0.15 mm, which was embedded at different depths within the silicone (on the surface, 1 mm depth and 2 mm depth). The multilayered soft skin was also able to detect the temperature of the object during grasping, suggesting its potential application as a soft gripper in robotic systems.

Antidehydration and Stable Mechanical Properties during the Phase Transition of the PNIPAM-Based Hydrogel for Body-Temperature-Monitoring Sensors.

Poly(N-isopropylacrylamide) (PNIPAM) enhances the reversibility and responsiveness of wearable temperature-sensitive devices. However, an open question is whether and how the hydrogel design can prevent adhesive performance loss caused by phase-transition-induced dehydration and unstable mechanical properties between devices and human skin and reduce interfacial failure. Herein, a gelatin-mesh scaffold-based hydrogel (NAGP-Gel) is constructed to inhibit dehydration and volume change, leading to stable mechanical properties, superior adhesiveness, and thermal sensing sensitivity during the phase transition. NAGP-Gel enhances the polymer chains-water interaction and weakens the degree of aggregation of polymer chains-chains, improving antidehydration properties under 45 °C conditions that are higher than the lower critical solution temperature (LCST; i.e., ∼32 °C). The mesh scaffold greatly restricts the phase-transition-induced polymer chain movement and maintains the mechanical performance. In a 60 °C environment, the maximum water loss and volume retention ratio of NAGP-Gel are only 3.58% and 97.3%, respectively. Additionally, NAGP-Gel serves as a temperature sensor, producing a stable thermal-electrical signal within the LCST range. It also can be assembled into an electronic device enabling the transmission of information and recognition of sign language via Morse code. This work broadens the application of PNIPAM in constructing intelligent hydrogels and opens the door to exploring emerging hydrogels for temperature-monitoring applications.

Internet based highly secure data transmission system in health care monitoring system

<span>The health care systems in our contemporary countries are advancing rapidly in terms of maturity and professionalism. In an effort to alleviate the current burden on the public health system and boost the popularity of regular health self-checks, this method has been developed for producing prediagnoses that are easier to use, quicker, and more accurate. To ascertain how well the heart is circulating oxygen throughout the body, a pulse test, a painless examination that measures an individual's degree of oxygen saturation, is used. It can be used to evaluate the state of any patient with a disease, particularly those with pulmonary problems. Diseases in these patients could need ongoing observation and care. Our system comes to the rescue in order to resolve this problem. This portable system is simple to use and may be taken anywhere by the subject. The internet of things (IoT) will update the pertinent parameters. This health monitoring system's controller is made up of an adaptor, a saturation of peripheral oxygen (SPO2 ) sensor (a blood oxygen meter), a temperature sensor, a heart rate sensor, a WiFi module, and a liquid crystal display (LCD).</span>

Integrated all-fiber-optic sensor based on FPI and MZI composite structures for temperature and strain measurement

In this paper, a temperature and strain sensor based on fiber-optic Mach-Zehnder interferometer (MZI) cascaded with Fabry-Perot interferometer (FPI) is designed and fabricated. The integrated sensor structure consists of no-core fiber (NCF) sandwiched by two sections of multi-mode fiber (MMF), hollow-core fiber (HCF), and two single-mode fibers (SMF) which are cascaded at the ends of the MMF and the HCF. Due to the thermal expansion effect, thermo-optic and elasto-optic effects of fiber material, the increase of the temperature and strain will make the change of the transmission mode, which will cause the spectral fringes wavelength shifting with strain, and the intensity of the spectral fringes varying with temperature but not strain variations in multiple temperature ranges. The series experiments valid show that the sensor with integrated structure realizes the strain and temperature measurements in multiple temperature ranges, and the minimum and maximum temperature sensitivities are -0.278dBm/°C and -0.670dBm/°C in the temperature range of 68-86 °C and 123-141 °C, respectively. The strain sensitivity is 2.17pm/με all over the measured range. The integrated sensor structure has the advantages of high sensitivity, multiple measuring ranges, simple manufacturing, and low cost, which has the potential to be applied in the field of the internal strain and temperature measurements of different structures.

Vibrational coupling-based multilayer flexible triboelectric nanogenerator for wide-amplitude omnidirectional wave energy harvesting

Wave energy harvesters are viewed as potential foundations for self-powered wireless sensor devices. In this study, a multilayer flexible triboelectric nanogenerator (MFLU-TENG) is proposed and evaluated, which combines the stretching properties of springs and the deformation properties of flexible materials to enable wide-wavelength energy harvesting. It captures wave energy even at very low amplitudes, requiring a minimum wave amplitude of 5 cm for energy recovery. The study explores how geometric parameters of the MFLU-TENG affect vibration behavior and output performance. Optimal performance is achieved when varying the thickness of the PETG cushioning layer, resulting in a peak power density of up to 7.7 mW/m2. Three MFLU-TENGs connected in parallel successfully power 15 LEDs. And four parallel groups of MFLU-TENGs charged a 100µF capacitor to 5.3 V in 198 s and successfully powered the temperature and humidity sensor. And the MFLU-TENGs charge the 100uf capacitor to 4.0v and power the clock in 153 s. These findings underscore the MFLU-TENG’s potential as a cost-effective and efficient wave energy harvesting device, using renewable wave energy to power sensors or microelectronic devices in the Internet of Things.

Research on humidity field and freezing resistance of green recycled ceramic internal cured concrete at early age

In cold and drought environment, concrete shrinkage cracking caused by water loss is serious, and thus the freezing resistance of concrete is deteriorated. The waste ceramic particles were used as internal curing materials to prepare concrete, based on this background. Then, the influence of internal curing with ceramic particles on humidity field and temperature of concrete is analyzed by using temperature and humidity sensor. Based on the change mechanism of the internal humidity of concrete, the relationship between the curvature radius of liquid surface and the relative humidity is revealed. Taking water loss and water loss rate as the index, the water transfer law of concrete surface under ceramic particle internal curing was defined. Through the drying shrinkage test, the mechanism of improving the drying shrinkage of concrete by internal curing in ceramic particles was mastered. Finally, the effects of ceramic internal curing on cement hydration, interfacial transition zone (ITZ) and freezing resistance of concrete were studied. The results show that the relative humidity, water loss and water loss rate of concrete increase with the increase of ceramic particle content, and the dry shrinkage value decreases with the increase of ceramic particle content. Compared with ordinary concrete, when the ceramic particle content is 10%, 15%, 20%, 25% and 30%, and the test period is 10 days, the internal relative humidity of concrete increases by 0.52%, 0.67%, 1.55%, 2.55% and 3.05%, respectively. The drying shrinkage values decreased by 3.42%, 7.69%, 10.26%, 15.17% and 30.13%, respectively. When the test period was 1032 hours, the water loss increased by 1.08%, 5.15%, 7.90%, 12.69% and 14.49%, respectively. Furthermore, when the ceramic particle content is 20%, the initial normalized heat flow of concrete increases by 2.74 mW/g, and the normalized heat flow minimum increases by 0.324 mW/g. The minimum ITZ microhardness increased by 2.64 MPa, the ITZ width decreased by 5 μm, and the maximum crack width at the contact between ITZ and aggregate decreased by 0.89 μm. At the same time, when the ceramic particle content is less than 20%, the effect of internal curing on the freezing resistance of concrete increases with an increase in ceramic particle content.

Femtosecond Laser-Inscribed Cladding Mode Small-Period Long-Period Fiber Gratings for Temperature and Strain Sensing

Femtosecond Laser-Inscribed Cladding Mode Small-Period Long-Period Fiber Gratings for Temperature and Strain Sensing

A 4H-SiC NMOSFET-Based Temperature Sensor Operating Between 14K and 481 K

A 4H-SiC NMOSFET-Based Temperature Sensor Operating Between 14K and 481 K

Development of integrated monitoring technology for hypothermia and hypoxia in low birth weight infants

Hypothermia and hypoxia are two conditions that often occur in Low Birth Weight (LBW) infants and can lead to serious complications if not promptly detected and addressed. The aim of the research is to develop a prototype of a medical device that integrates the detection of hypothermia and hypoxia in low birth weight infants. The research method uses a Research and Development approach. (R&D). The development process is carried out through several stages, namely needs analysis, design, development, testing, and evaluation. In the needs analysis stage, data is collected based on the results of previous research and through a literature review to determine the expected specifications of the tool. Next, in the design and development stage, the prototype is designed by integrating temperature sensors and an oximeter, as well as an automatic alarm system that provides early warnings when the baby's vital parameters are outside normal limits. In the initial stage, testing is conducted through simulations. The research results show that the prototype is capable of quickly detecting changes in body temperature and oxygen levels, as well as providing an alarm response to any abnormal changes. In further development, functional testing of the device will be conducted on infants. This device is expected to contribute to the improvement of neonatal care quality and the reduction of infant mortality rates due to complications from hypothermia and hypoxia.

Performance optimization of AlN ultrasonic thin-film sensors deposited by RF magnetron sputtering

The AlN thin-film ultrasonic transducers were deposited by reactive RF magnetron sputtering technique. The effects of deposition parameters: target-substrate distance, argon-nitrogen flow ratio, deposition time, substrate temperature and radial distance from the deposition center on the ultrasonic performance of AlN thin films were studied. A metal electrode layer was deposited on the AlN film transducer to fabricate an ultrasonic temperature sensor, and the effects of the size and thickness of the electrode layer on the performance of the sensor were studied. Piezoelectric response measurements were performed in air over a temperature range of −60 °C–900 °C, and the dependence of ultrasonic response (time-of-flight and pulse echo amplitude) on temperature was analyzed. Long-term heat treatment in air at 750 °C for 128 h showed that the high-entropy alloy oxide protective layer could effectively delay oxidation of the AlN layer and improve the service life of the sensor.

Relating ten years of rock temperature monitoring to rockwall weathering processes in steep mountain valleys in western Norway

Most existing studies on rockwall frost regimes and frost weathering at rockwalls focus on permafrost-affected rockwalls. However, a high share of rockwall surface areas in Norway and in many other cold-climate environments is actually free of permafrost. It is therefore of interest how these permafrost-free rockwall systems will respond to future changes in air and rock temperatures. In this study, we report field measurements conducted at rockwalls beneath the current permafrost limit and investigate thermal regimes at rockwalls that include both rockwall areas with and without permafrost. We present a unique dataset of up to ten years of rockwall temperature measurements from ten temperatures sensors installed in two mountain valleys in western Norway. An analysis of the different rockwall thermal regimes with respect to rock weathering and associated rockfall supply for both, permafrost-affected and permafrost-free rockwalls is provided. The highest intensity of recent rockwall weathering including determined rockwall retreat rates and associated rockfall supply is detected for northeast-facing rockwalls followed by south-facing rockwalls in our study area. Frost cracking activity, probably in the form of segregation ice growth, seems to be an important factor particularly for the high weathering intensity on northeast-facing rockwalls whereas solar radiation-induced thermal stresses, which favour incremental subcritical crack growth, is assumed to play a relevant role in the moderate weathering intensity on south- and southwest-facing rockwalls. A mean annual and study area-wide rockwall retreat rate of 0.24 mm yr−1 is estimated for our ten-year investigation period (2010−2020) which is comparable to other published rates in similar lithologies and climates. As it can be assumed that seasonal frost regimes and permafrost will react differently to ongoing and future climate changes, more attention should be paid to analyse these two different thermal regimes with respect to possible varied implications for mechanical rockwall weathering and associated rockfall supply.

Investigating temperature fluctuations in the wine and liquor maritime supply chain from South Africa to the United Kingdom: A case study

This study explored temperature fluctuations in dry shipping containers transporting wine and liquor along maritime supply chains. It also examined how these variations affect product quality, and evaluated the effectiveness of thermal foil container liners in mitigating temperature changes. Temperature trials were conducted from the South African loading depot and concluded at the first distribution centre in the United Kingdom. Ambient temperature sensors were placed on cartons of wine and liquor inside the thermal container liner and between the thermal liner and the door of the container. Weather data was also collected during the trials. Temperature profiles showed large fluctuations in temperature inside containers because of day and night cycles while the containers were stacked at the departure and destination ports, posing challenges for supply chain management. Descriptive statistics were used to analyse the temperature profiles, whereas logit analysis was used to determine the impact of the thermal container liner on the temperatures to which the wine and liquor were exposed. Blind tastings were used to evaluate product quality after exposure to temperature fluctuations. Results showed that thermal liners significantly reduced temperature variability, which is critical for maintaining wine and liquor quality. Despite this, blind tastings confirmed that some products were negatively affected by temperature deviations. The study recommends the use of thermal foil liners for maritime transport of wine and liquor to minimise product damage and financial losses. This finding is particularly relevant for exporters aiming to preserve the quality of their wine and liquor throughout long-distance shipping routes.

Design and Investigation of a High-Performance Quartz-Based SAW Temperature Sensor

In this work, a surface acoustic wave (SAW) temperature sensor based on a quartz substrate was designed and investigated. Employing the Coupling-of-Modes (COM) model, a detailed analysis was conducted on the effects of the number of interdigital transducers (IDTs), the number of reflectors, and their spacing on the performance of the SAW device. The impact of the transversal mode of quartz SAWs on the device was subsequently examined using the finite element method (FEM). The simulation results indicate that optimizing these structural parameters significantly enhances the sensor’s sensitivity and frequency stability. SAW devices with optimal structural parameters were fabricated, and their resonant frequencies were tested across a temperature range of 25–150 °C. Experimental results demonstrate that the SAW temperature sensor maintains high performance stability and data reliability throughout the entire temperature range, achieving a Bode-Q of 7700. Furthermore, the sensor exhibits excellent linearity and repeatability. An analysis of the sensor’s response under varying temperature conditions reveals a significant temperature dependency on its Temperature Coefficient of Frequency (TCF). This feature suggests that the sensor possesses potential advantages for applications in industrial process control and environmental monitoring.