Wireless Temperature Research Articles

An alumina ceramic inspired high temperature wireless chipless sensor for harsh environment

This paper proposes a wireless passive temperature sensor. The sensitive material as the substrate of the sensor employs an alumina ceramic. The resonator of the sensor is a split ring, which is printed with copper on the substrate. The dimensions of the split ring resonator are optimized to improve the temperature sensitivity of the sensor. A change in environment temperature will lead to a change in the dielectric constant of the sensitive material, thus resulting in the shift of the resonant frequency of the sensor. The variation range of the dielectric constant of the sensitive material is 10.17–11.2 corresponding to 500–1000 °C. The resonant frequency of the signal backscattered from the sensor is obtained through the simulation software with HFSS. The simulation results show that the resonant frequency of the sensor decreases from 5.84 to 5.56 GHz with temperature increasing from 500 to 1000 °C and the temperature sensitivity is 0.56 MHz/°C. The high temperature sensor has the characteristics of wireless and passive operation, low profile, and high sensitivity. It can be widely adapted to a variety of high temperature and harsh environments.

A microwave resonance thin-film sensor for real-time wireless temperature monitoring in composites manufacturing

Composites are of growing importance to today's industries. Curing or consolidation under certain temperatures is a vital process to manufacture composite parts. Great attention has been paid to monitoring the temperature of composite parts being processed. Wireless monitoring methods are extensively explored for their unique advantages in realizing real-time monitoring of specific temperature distribution of the part. Here, a flexible microwave resonance sensor is first introduced to achieve real-time wireless temperature monitoring of composites. When applied to curing processes with different heating rates, it was found that the sensing relationship of the sensor was varied. Through in-depth analysis, the relationship between peak frequencies and temperature was established with consideration of different heating rates. In several curing processes with different heating rates, the mean error of the thin film sensor using a heating rate-related relationship was about 4.23 °C. which can be reduced by more than 43 % compared with the method using a static relationship.

Nanocomposite Electret Layer Improved Long-Term Stable Solid-Liquid Contact Triboelectric Nanogenerator for Water Wave Energy Harvesting.

With the continuous rise of environmental pollution and energy crisis, the global energy revolution is risen. Development of renewable blue energy based on the emerging promising triboelectric nanogenerators (TENG) has become an important direction of future energy development. The solid-liquid contact triboelectric nanogenerator (TENG) has the advantages of flexible structure, easy manufacture, and long-term stability, which makes it easier to integrate and achieve large-scale conversion of wave mechanical energy. However, the electric power output is still not large enough, which limits its practical applications. In this work, a nanocomposite electret layer enhanced solid-liquid contact triboelectric nanogenerator (E-TENG) is proposed for water wave energy harvesting, which can effectively improve the electric output and achieve real-time power supply of wireless sensing. Through introducing a nanocomposite electret layer into flexible multilayer solid-liquid contact TENG, higher power output is achieved. The E-TENG (active size of 50mm×49mm) shows desired output performance, a power density of 521mWm-2. The generated electric energy can drive wireless temperature sensing by transmitting wireless signals carrying detection information at the period of ˂5.5min. This research greatly improves the electric output and provides a solid basis for the industrialization of TENG in blue energy.

Optimization of number of wireless temperature sensors using clustering algorithm for deep learning algorithm-based Kimchi quality prediction

The production and storage of kimchi in a factory require monitoring temperature and humidity to maintain optimal quality. Recently, smart packaging devices such as wireless sensors have been used, but their installation and maintenance are costly and require additional resources. In this study, kimchi is packaged in polyethylene packages and placed in plastic baskets. Thirty baskets are stacked in the middle of the storage room. Wireless sensors placed inside the baskets collect temperature data alongside the kimchi for 60 days. The data is sent to a server through communication unit using 4G network. Two clustering algorithms, Competitive Learning Neural Network (CLNN) and k-means, are used to determine the optimal number and location of sensors. Deep learning algorithms, specifically Long Short-Term Memory (LSTM), predict the acidity and ripeness grade of the kimchi. The study found that the optimal number of temperature sensor groups for CLNN was 6 for acidity and 4 for ripeness grade classification. Increasing the number of sensors improved the kimchi acidity prediction, and the accuracy of ripeness classification increased with the number of sensors. The location of the wireless sensors was determined based on the heights of the stacked plastic baskets using the CLNN + LSTM model. This work presents a process for optimizing sensor placement and evaluating kimchi quality during storage and fermentation using clustering and deep learning techniques to maintain optimal quality.

A Wrinkle‐Enhanced Porous Poly(lactic Acid) Electret‐based Nanogenerator for Self‐powered Wireless Temperature Measurement Systems

AbstractRecently, electret‐based triboelectric nanogenerator (E‐TENG) showssignificant advantages for energy harvesting applications, including a largeelectric current and high output stability. Inthis investigation, porous biocompatible polylactide (PLA) film is prepared for E‐TENG applications. They found that thesurface potential of the porous PLA‐based bioelectret film is maintained at2.1 kV after 86 days of decay,. The measurement data from theE‐TENG‐based cantilever beam showed that the E‐TENG reached an open‐circuitvoltage (Voc) of 184 V and a short circuit current (Isc)of 22.4 µAat 13.8 Hz. Furthermore, the E‐TENG and the PVDF‐based piezoelectric nanogenerator (PENG) are combined to create a hybridNG for energy harvesting applications. The data indicate that the maximumoutput power of the hybrid NG reached 73.5 µWat 6 MΩ,which is 30.7% and 1.91‐fold higher than that of the PENG and the E‐TENG,respectively. The hybrid NG is used as a powersource to drive a wireless temperaturetransmission system, which can receive a temperature transmission signal from 20 m away. The advantages of biocompatibility,softness and ease of processing make the porous PLA film a great candidate forwearable devices applications.

High-performance piezoelectric energy harvesting system with anti-interference capability for smart grid monitoring

This paper presents a piezoelectric energy harvesting device with anti-interference capability. The device utilizes magnetic coupling between the magnet at the tip of the piezoelectric cantilever and the alternating magnetic field surrounding power lines to efficiently harvest energy. Three piezoelectric cantilever structures are designed to optimize energy harvesting efficiency and space utilization. The impact of magnet interaction on the energy harvesting performance is investigated through theoretical analysis and experiments. The results demonstrate a decrease in the natural frequency of each piezoelectric cantilever due to magnet interaction. Frequency compensation techniques are applied to improve the overall output of the device. The anti-interference capability of the harvester is thoroughly evaluated, showing stable output even under random acceleration and the ability to withstand external interference. Additionally, the device successfully powers a wireless temperature and humidity sensor, validating its potential for self-powered wireless sensing nodes in grid monitoring systems.

A disposable reader-sensor solution for wireless temperature logging

A disposable reader-sensor solution for wireless temperature logging

Temperature-dependent electrical and dielectric behavior of polymer-derived SiAlCN ceramics

Polymer-derived SiAlCN ceramics as sensing materials are promising materials for wireless temperature sensors to achieve application in high-temperature harsh environments. However, limited understanding for the electric and dielectric properties of SiAlCN ceramics restricts the development of wireless sensors. Herein, the electrical and dielectric properties of polymer-derived SiAlCN ceramics pyrolyzed at different temperatures are investigated systemically. The results reveal that the electric resistance of the free-carbon phase and amorphous SiAlCN ceramic phase are comparable, however, the dielectric constant of the ceramic phase is much higher than that of the free-carbon phase. The maximum dielectric constant can reach up to 2.4E+5. Furthermore, the detailed mechanism analysis reveals that the SiAlCN ceramics with different pyrolysis temperatures all obey the same relaxation process, which is interfacial polarization and non-Debye relaxation. The deep understanding of the dielectric property of polymer-derived SiAlCN ceramics is very practical to design wireless sensors for potential applications in high-temperature and harsh environments.

Self‐Powered Wireless Temperature Monitor System Based on Triboelectric Nanogenerator with Machine Learning

Triboelectric nanogenerator (TENG) can power wireless, real‐time sensing system with hybrid electromagnetic or piezoelectric power, or directly drive commercial LED without battery. However, it is a great challenge to directly drive wireless real‐time sensing system due to low energy density based on environment energy. Here, a self‐powered smart wireless temperature monitoring system that uses machine learning to accurately measure the ambient temperature is developed. A position modulation‐based TENG‐driven transmitter enables wireless communication and real‐time temperature monitoring. This machine learning‐based wireless sensor can accurately monitor the ambient temperature, with a recognition accuracy of up to 96.2%. This sensor architecture could potentially be used in low‐cost distributed sensors for environmental monitoring.

Wide Remote-Range and Accurate Wireless LC Temperature-Humidity Sensor Enabled by Efficient Mutual Interference Mitigation.

Inductor-capacitor wireless integrated sensors (LCWISs) featuring untethered and multitarget measurements are promising in health monitoring and human-machine interfaces. However, the lack of a profound understanding of the internal interference hinders the design of the LCWIS, which has a wide remote sensing range and high accuracy. Herein, a mutually exclusive effect of the mutual inductance interferences in LCWIS was revealed and quantified, enabling a design with a wide range of remote sensing (working distance comparable to the single-target device, working radius: 4 mm) and 16% reduced area. As a key to accurate multitarget measurement, a quantified target interference model based on interference decomposition was proposed to understand the target interferences, providing profound guidance for the design of ultra-accurate LCWIS. As a proof, we designed a cellulose-polyacrylate-cellulose LCWIS (CPC-LCWIS) with ultrahigh accuracies (∼1.2% RH and ∼0.18 °C) beyond commercial wired gauges. The CPC-LCWIS with full-coil sensing structures achieved exceptionally high sensitivities (0.36 MHz/°C and 0.25 MHz/% RH). The CPC-LCWIS was validated for health monitoring and human-machine interfaces. The concept studied in this work provides profound guidance for designing a high-performance flexible LCWIS for advanced wearable electronics.

Correlation Between 6 Characteristics of Perioperative Hypothermia and Allogeneic Red Blood Cell Transfusion in Abdominal Surgery Patients

To explore the correlation between six characteristics of perioperative hypothermia and allogeneic red blood cell (RBC) transfusions in patients who underwent abdominal surgeries. Patients who underwent abdominal surgeries at West China Hospital, Sichuan University between October 2019 and July 2021 were retrospectively enrolled. A wearable wireless temperature sensor was used to continuously monitor the core body temperature of patients throughout the perioperative period. The perioperative temperature nadir, maximum temperature loss, percentage of time with hypothermia, time-weighted average temperature, area under the curve (AUC) at 36 ℃, and AUC at 37 ℃ were calculated for the period from entering the operation room to 24 hours after the end of anesthesia. The restricted cubic spline (RCS) and multiple logistic regression models were used to explore the correlation between these temperature characteristics and perioperative allogeneic RBC transfusions. A total of 3119 patients were included in the study, with an allogeneic RBC transfusion rate of 2.8%. The RCS model showed that allogeneic RBC transfusion was associated with the perioperative temperature nadir (Poverall=0.048) and AUC at 36 ℃ (Poverall=0.026) and no statistical significance was found in the nonlinear test. The association between allogeneic RBC transfusions and other temperature characteristics was not statistically significant. According to the RCS model results, cut-off points were taken to form groups based on the body temperature characteristics. Multivariate logistic regression showed that the perioperative temperature nadir<35.5 ℃ (odds ratio [OR]=2.47, 95% confidence interval [CI]: 1.21-5.03) and AUC at 36 ℃≥100 ℃·min (OR=2.24, 95% CI:1.09-4.58) were associated with increased demand for allogeneic RBC transfusion. Hypothermia is associated with an increased need for perioperative allogeneic RBC transfusions and has a cumulative effect over time. For patients at high risk of bleeding, attention should be paid to the prevention of perioperative hypothermia and reduction in the cumulative exposure to hypothermia, thereby reducing the need for blood transfusion.

Enhance vortices vibration with Y-type bluff body to decrease arousing wind speed and extend range for flag triboelectric energy harvester

The Internet of Things (IoT) has approached network construction by billions of intelligent wireless sensor nodes (WSNs). The major challenge is the desirable self-power generator by environment local energy. This paper presents a novel flag-type triboelectric nanogenerator with a Y-type bluff body that is YF-TENG to harvest wind energy. It exhibits a wider range and lower wind velocities for energy harvesting. The Y-type bluff body enhances YF-TENG vibration of the vortices shedding which is recorded by high-speed camera. The mounting position, designing dimension, and windward angle of the Y-type bluff body are investigated to enhance the flag vibration and the output triboelectric power. The test results show that the power is twice as much as the traditional flag-type triboelectric nanogenerator with a wind velocity of 6 m/s. Furthermore, a proof-of-concept application of the arrayed YF-TENG units supplies sufficient electric power for the wireless temperature and humidity sensor in a wind tunnel. It is envisioned that the enhancement of YF-TENG sensitivity and stability via a Y-type bluff body affords significant potential power for a large number of sensor nodes in a wide wind region.

Wireless Strain and Temperature Monitoring in Reinforced Concrete Using Surface Acoustic Wave Sensors

Wireless Strain and Temperature Monitoring in Reinforced Concrete Using Surface Acoustic Wave Sensors

Research and experiment the wireless passive surface acoustic wave technology for conductor temperature monitoring of high voltage equipment

This paper presents the research and design of a passive thermal monitoring system using wireless temperature sensors based on the principle of surface acoustic wave (SAW). The monitoring system is employed on components that need to be monitored for heat generation, including switch contacts, busbars, and cable connections at switchgears or ring main units (RMUs). The basic impulse insulation level (BIL), or voltage spike tolerance, of the wireless SAW temperature sensor utilised in this study, means that it is not necessary to power it with sensors that meet the high criteria for equipment installed in closed cabinets or medium voltage cabinets. The research team’s activities in this study included software development, data transmission design and manufacture, and sensor selection. The system functions steadily, with a temperature error of no more than 2oC, according to the test findings under laboratory settings.

Deformations caused by subsurface heat islands: a study on the Chicago Loop

Deformations caused by subsurface heat islands: a study on the Chicago Loop

Implementation of Building a Thermal Model to Improve Energy Efficiency of the Central Heating System—A Case Study

This paper presents the concept of an innovative control of a central heating system in a multifamily building based on the original thermodynamic model, the resulting architecture of the control system, and the originally designed and manufactured wireless temperature sensors for thermal zones. The novelty of this solution is the developed layers of the control system: distributed measurement and correction analysis, which is based on the existing infrastructure and the local HVAC controller. This approach allows for the effective use of the measured temperature data from thermal zones and finally sending the value of the calculated correction of settings to the controller. Moreover, in the analytical layer, a model was also implemented that calculates the necessary amount of energy based on data from the subsystem of temperature sensors located in the thermal zones of the building. The use of the algorithmic strategy presented in this paper extends the functionality and significantly improves the energy efficiency of the existing, classic, reference heating control algorithm by implementing additional control loops. Additionally, it enables integration with demand-side response systems. The presented concept was successfully tested, achieving real energy savings for heating by 12%. These results are described in a case-study format. The authors believe that this concept can be used in other buildings and thus will have a positive impact on the energy savings used to maintain thermal comfort in buildings and significantly reduce CO2 emissions.

Development of Temperature Sensor Based on AlN/ScAlN SAW Resonators

Temperature monitoring in extreme environments presents new challenges for MEMS sensors. Since aluminum nitride (AlN)/scandium aluminum nitride (ScAlN)-based surface acoustic wave (SAW) devices have a high Q-value, good temperature drift characteristics, and the ability to be compatible with CMOS, they have become some of the preferred devices for wireless passive temperature measurement. This paper presents the development of AlN/ScAlN SAW-based temperature sensors. Three methods were used to characterize the temperature characteristics of a thin-film SAW resonator, including direct measurement by GSG probe station, and indirect measurement by oscillation circuit and antenna. The temperature characteristics of the three methods in the range of 30–100 °C were studied. The experimental results show that the sensitivities obtained with the three schemes were −28.9 ppm/K, −33.6 ppm/K, and −29.3 ppm/K. The temperature sensor using the direct measurement method had the best linearity, with a value of 0.0019%, and highest accuracy at ±0.70 °C. Although there were differences in performance, the characteristics of the three SAW temperature sensors make them suitable for sensing in various complex environments.

Self-Powered Wireless Temperature and Vibration Monitoring System by Weak Vibrational Energy for Industrial Internet of Things.

Developing self-powered smart wireless sensor networks by harvesting industrial environmental weak vibration energy remains a challenge and an impending need for enabling the widespread rollout of the industrial internet of things (IIoT). This work reports a self-powered wireless temperature and vibration monitoring system (WTVMS) based on a vibrational triboelectric nanogenerator (V-TENG) and a piezoelectric nanogenerator (PENG) for weak vibration energy collection and information sensing. Therein, the V-TENG can scavenge weak vibration energy down to 80 μm to power the system through a power management module, while the PENG is able to supply the frequency signal to the system by a comparison circuit. In an industrial vibration environment where the vibration frequency and amplitude are 20 Hz and 100 μm, respectively, the WTVMS can upload temperature and frequency information on the equipment to the cloud in combination with the narrowband IoT technology to realize real-time information monitoring. Furthermore, the WTVMS can work continuously for more than 2 months, during which the V-TENG can operate up to 100 million cycles, achieving ultrahigh stability and durability. By integrating weak vibration energy harvesting and active sensing technology, the WTVMS can be used for real-time online monitoring and early fault diagnosis of vibration equipment, which has great application prospects in industrial production, machinery manufacturing, traffic transportation, and intelligent IIoT.

Printing Three-Dimensional Refractory Metal Patterns in Ambient Air: Toward High Temperature Sensors.

Refractory metals offer exceptional benefits for high temperature electronics including high-temperature resistance, corrosion resistance and excellent mechanical strength, while their high melting temperature and poor processibility poses challenges to manufacturing. Here this work reports a direct ink writing and tar-mediated laser sintering (DIW-TMLS) technique to fabricate three-dimensional (3D) refractory metal devices for high temperature applications. Metallic inks with high viscosity and enhanced light absorbance are designed by utilizing coal tar as binder. The printed patterns are sintered into oxidation-free porous metallic structures using a low-power (<10W) laser in ambient environment, and 3D freestanding architectures can be rapidly fabricated by one step. Several applications are presented, including a fractal pattern-based strain gauge, an electrically small antenna (ESA) patterned on a hemisphere, and a wireless temperature sensor that can work up to 350°C and withstand burning flames. The DIW-TMLS technique paves a viable route for rapid patterning of various metal materials with wide applicability, high flexibility, and 3D conformability, expanding the possibilities of harsh environment sensors.

The Architecture for Testing Central Heating Control Algorithms with Feedback from Wireless Temperature Sensors

The energy consumption of buildings is a significant contributor to overall energy consumption in developed countries. Therefore, there is great demand for intelligent buildings in which energy consumption is optimized. Online control is a crucial aspect of such optimization. The implementation of modern algorithms that take advantage of developments in information technology, artificial intelligence, machine learning, sensors, and the Internet of Things (IoT) is used in this context. In this paper, an architecture for testing central heating control algorithms as well as the control algorithms of the heating system of the building is presented. In particular, evaluation metrics, the method for seamless integration, and the mechanism for real-time performance monitoring and control are put forward. The proposed tools have been successfully tested in a residential building, and the conducted tests confirmed the efficiency of the proposed solution.