Ceramic Sensors Research Articles

A Ceramic Heat Flux Sensor With High Sensitivity for Ultrahigh Temperature

A Ceramic Heat Flux Sensor With High Sensitivity for Ultrahigh Temperature

AE-IRMamba: Low-Complexity Inverted Residual Mamba for Identification of Piezoelectric Ceramic and Optical Fiber Acoustic Emission Sensors Signals

AE-IRMamba: Low-Complexity Inverted Residual Mamba for Identification of Piezoelectric Ceramic and Optical Fiber Acoustic Emission Sensors Signals

Development of Additively Manufactured Embedded Ceramic Temperature Sensors via Vat Photopolymerization

Current additive manufacturing (AM) techniques and methods, such as liquid-crystal display (LCD) vat photopolymerization, offer a wide variety of surface-sensing solutions, but customizable internal sensing is both scarce in presence and narrow in scope. In this work, a fabrication process for novel customizable embedded ceramic temperature sensors is investigated. The fabrication techniques and materials are evaluated, followed by extensive characterization via spectral analysis and thermomechanical testing. The findings indicate that LCD-manufactured ceramic sensors exhibit promising sensing properties, including strong linear thermal sensitivity of 0.23% per °C, with an R2 of at least 0.97, and mechanical strength, with a hardness of 570 HV, making them suitable for adverse environmental conditions. This research not only advances the field of AM for sensor development but also highlights the potential of LCD technology in rapidly producing reliable and efficient ceramic temperature sensors.

Development and Manufacturing Method of Electrodes for a High Temperature Oxygen Sensor

The article discusses the use of zirconium dioxide stabilized with yttria as an electrolyte for the formation of a high-temperature ceramic oxygen concentration sensor. The fundamental possibility of using such a material is due to the high electrical conductivity caused by the mobility of oxygen ions in the vacancies of the solid electrolyte. The operating principle of such a sensor as an electrochemical concentration element is discussed. It has been shown that the use of such sensors is relevant for various industries (including chemical, metallurgical, oil and gas, energy and others). Options for forming electrodes of an electrochemical sensor using various materials and deposition methods are considered. A method for forming a platinum coating using a chemical method using isopropyl alcohol and subsequent pyrolysis was tested. It has been experimentally shown that the chemical method is applicable for the formation of electrodes of an electrochemical sensor. The electrical characteristics of the resulting coatings were measured. The optimal composition of the reaction mixture and the required number of layers to create a stable operating electrochemical sensor have been determined. The dependence of the potential of the formed electrochemical sensor from stabilized zirconium oxide on oxygen concentration in a wide temperature range has been studied. It has been shown that when using a scheme of sequential transformations, hydrolysis of platinum tetrachloride - deposition on a substrate - reductive pyrolysis, it is possible to obtain a high-quality conductive coating for the formation of gas sensor electrodes. The optimal composition of the reaction mixture for the formation of platinum electrodes has been selected. The optimal number of layers was determined to ensure the required level of electrical conductivity of the electrodes. It has been shown that an electrochemical element based on zirconium dioxide and platinum electrodes, formed according to the scheme developed in this work, can be used as a high-temperature oxygen sensor.

Evolution of dielectric properties of SiBCN ceramics and its derived wireless passive temperature sensor application

SiBCN ceramics derived from preceramic polymers are suitable candidates for high-temperature sensors due to their remarkable high-temperature stability and semiconducting properties. However, research into their dielectric performance together with relevant sensors is meaningful but inadequate. In this work, the correlation between dielectric properties and the structure of SiBCN ceramic is identified by studying the evolution trend of the chemical composition, microstructure, and dielectric properties with pyrolysis and environment temperature. SiBCN ceramic was prepared by powder pressing process and pyrolyzed at 1000–1400 °C. As the pyrolysis temperature increased, the dielectric constant and dielectric loss tangent of SiBCN ceramic gradually increased. Within the test temperature range of 500 °C, the dielectric loss was mainly polarization loss. In addition, SiBCN ceramic wireless passive temperature sensors were prepared to test their performance from room temperature to 500 °C. The results showed that the sensitivity increased with the test temperature, and the transmission efficiency of the sensor was closely related to the dielectric properties, indicating that SiBCN ceramic has promising application prospects in the field of high-temperature sensing with good repeatability and stability.

Capacitive pressure sensors based on microstructured polymer-derived SiCN ceramics for high-temperature applications

Traditional silicon-based pressure sensors cannot meet demand of pressure information acquisition in high-temperature extreme environments due to their low sensitivity, limited detection temperature and complex processing. Herein, a capacitive pressure sensor is fabricated using polymer-derived SiCN ceramics with convex microstructures via a sample replication strategy. Its performance is measured at different pressures (0–800 kPa) from room temperature to 500 °C. The results show that the SiCN ceramic capacitive pressure sensor exhibits low hysteresis, good non-linearity of 0.26 %, outstanding repeatability and high sensitivity of 0.197 pF/MPa under room temperature. When the test temperature reaches 500 °C, the performance of the prepared capacitive pressure sensor has no degradation, keeping competent sensitivity of 0.214 pF/MPa and nonlinear error of 0.24 %. Therefore, benefitting from the preeminent high-temperature properties, e.g., excellent oxidation/corrosion resistance and thermal stability, SiCN ceramics capacitive pressure sensors have great potential in the application of high-temperature and harsh environments.

Measurement of sand particle motion speed in multiphase wind-sand flow based on piezoelectric ceramic sensors

Abstract Utilizing Pb(ZrTi)O3-5A piezoelectric ceramic (hereafter referred to as PZT-5A) as sensors, we studied the movement speed of sand particles in multiphase wind-sand flows. We developed a mathematical model that effectively links the impact force of sand grains with the output voltage of PZT-5A, incorporating factors such as the piezoelectric coefficient and sand particle characteristics. Additionally, we proposed a new method to accurately determine the elastic recovery coefficient of sand particles using PZT-5A sensor measurements and experimental setups, which is significant for the field of material science. Wind tunnel experiments revealed that at heights ranging from 0.1 to 1.0m, sand particle speeds range from 52.8% to 91.4% of wind speeds. As wind speed increases to 15m/s, sand particle speed nears 91.4% of wind speed. Yet, at a constant wind speed, sand speed drops as sediment discharge rises. This research offers fresh insights into sand particle dynamics in wind-sand contexts.

Ultrafast high-temperature sintering of polymer-derived ceramic thick film sensors

Polymer-derived ceramics (PDCs) find extensive applications as sensitive materials in in-situ thin/thick film sensors (TFSs) co-fabricated with components. However, the prolonged high-temperature sintering steps of PDCs inevitably lead to severe thermal damage to their co-sintered substrates. In this study, we employed an ultrafast high-temperature sintering (UHS) method, achieving rapid sintering of preceramic polymer slurry sensitive films in just a few minutes. Through direct ink writing technology, we patterned the preceramic polymer slurry, followed by UHS to prepare high-temperature ITO/SiCN TFSs. UHS-ITO/SiCN exhibited high sensitivity of microstructure, composition, and electrical characteristics to UHS parameters. The obtained ITO/SiCN resistance grid showed high electrical conductivity (706.89 S m−1 at room temperature), highly dense surface structure and excellent oxidation resistance. In an air atmosphere, the resistance drift rate of the resistance grid at 900 °C was only 0.54 %·h−1 without any protective layers. Finally, we fabricated an ITO/SiCN heat flux sensor with high sensitivity (78.75 mV/(kW·m−2)), a wide range (94.8 kW m−2), and excellent repeatability. This work has the potential to expand the application of UHS in the manufacturing of novel in-situ TFSs integrated with components.

A novel vinyl-bridged graphene oxide/polycarbosilane precursor for harsh environment-resistant ceramic temperature sensor

Ceramic temperature sensors are promising for automobile and jet engine monitoring but lack suitable materials and manufacturing methods. Herein, we designed and synthesized a novel vinyl-bridged graphene oxide/polycarbosilane (v-GO/PCS) hybrid precursor that could be easily shaped and pyrolyzed into reduced graphene oxide/silicon carbide (rGO/SiC) film as a stable and sensitive temperature sensor under harsh environments. As a result, 1 %-rGO/SiC ceramic film exhibited a fast response in the temperature range of 100 °C to 1000 °C. The rGO acted as a bridge linking the surrounding SiC grains, which significantly reduced the amount of thermal energy required for the directional transfer of electrons, leading to an increase in both the detection range and sensitivity of the sensor. The introduction of dry air, water vapor and acid (or alkali) atmosphere in the high-temperature conditions further verified its excellent stability. This work provides a simple and practicable strategy for highly stable temperature detection under harsh environments.

Mn-doped 0.67BiFeO3-0.33BaTiO3 ceramic sensor for high-temperature structural health monitoring

Real-time monitoring of structural health status is very important for supersonic aircraft, since the long-term operation in harsh service environments, such as high temperatures, can cause potential damage. Structural health monitoring (SHM) based on lamb wave has been approved to be a critical technique for the reliable operation of supersonic aircraft, but is limited by the operating temperature of conventional piezoelectric sensors, which makes it difficult to meet the high-temperature monitoring requirements. The BiFeO3–BaTiO3 ceramics exhibit excellent piezoelectric properties and high Curie temperature (Tc), making them promising for high-temperature SHM of supersonic aircraft. Here, we fabricated a piezoelectric sensor using 0.67BiFeO3-0.33BaTiO3-0.25%molMnO2 (BF33BTMN-025) ceramic, which exhibits a piezoelectric charge constant (d33) of 135 pC/N at room temperature and a Tc of 448 °C. The BF33BTMN-025 ceramic sensor operates effectively at temperatures up to 200 °C and maintains stable damage monitoring sensitivity as well. Compared with Pb(Zr, Ti)O3 (PZT), BaTiO3 (BTO) and other piezoelectric sensors commonly used in SHM field, the BF33BTMN-025 ceramic sensor has a higher operating temperature and a comparable sensitivity. Our work demonstrates that the BF33BTMN-025 ceramic sensor can be employed as piezoelectric sensor for high-temperature SHM, which has a wide application potential in the field of real-time monitoring of supersonic aircraft.

Subtractive manufacturing of polymer-derived ceramic composite thick film sensor based on ultrafast laser etching

Polymer-derived ceramics (PDCs) are increasingly recognized as promising materials for high-temperature thin/thick film sensors (HTTFSs). However, a large linewidth and poor dimensional accuracy have severely restricted the practical application of PDCs HTTFSs. Our study employed a picosecond laser to precisely pattern the polymer-derived ceramic (PDC) thick film while applying no obvious damage to the interface between ceramic and substrate. Through parameters optimization, the laser-affected area was minimized to 6 μm wide, and a minimum feature size of about 30 μm was achieved. Furthermore, 7 rounds of high-temperature tests of the patterned film revealed good temperature-resistance repeatability within a temperature range of up to 800 °C. To demonstrate practical application potential, we successfully fabricated a heat flux sensor, and it exhibited a sensitivity of 1.32 mV/(kW/m2), a response time of 600 ms, and excellent repeatability over a range of 0–75.4 kW/m2. In summary, this paper proposes a novel approach toward miniaturizing the linewidth of the polymer-derived ceramics thick film sensor, showing significant potential for precise measurements in extreme environments.

A Time-Frequency Domain Mixed Attention-Based Approach for Classifying Wood-Boring Insect Feeding Vibration Signals Using a Deep Learning Model.

Wood borers, such as the emerald ash borer and holcocerus insularis staudinger, pose a significant threat to forest ecosystems, causing damage to trees and impacting biodiversity. This paper proposes a neural network for detecting and classifying wood borers based on their feeding vibration signals. We utilize piezoelectric ceramic sensors to collect drilling vibration signals and introduce a novel convolutional neural network (CNN) architecture named Residual Mixed Domain Attention Module Network (RMAMNet).The RMAMNet employs both channel-domain attention and time-domain attention mechanisms to enhance the network's capability to learn meaningful features. The proposed system outperforms established networks, such as ResNet and VGG, achieving a recognition accuracy of 95.34% and an F1 score of 0.95. Our findings demonstrate that RMAMNet significantly improves the accuracy of wood borer classification, indicating its potential for effective pest monitoring and classification tasks. This study provides a new perspective and technical support for the automatic detection, classification, and early warning of wood-boring pests in forestry.

Controllable sintering behaviors of Al2O3 green tapes and co-firing compatibility of Al2O3/YSZ ceramics

As a typical insulating material, Al2O3 serves as the signal isolation device in multi-layer ceramic NOx sensors. However, the application of Al2O3-based insulating materials is limited by the co-firing compatibility between Al2O3 and yttria-stabilized zirconia (YSZ). In the present study, Al2O3 green tapes with different contents of γ-Al2O3 and SiO2–B2O3 (Si–B) are developed to promote the integration of Al2O3-based insulating material and YSZ. The sintering shrinkage of the obtained Al2O3 green tapes is greatly influenced by the ratio of γ-Al2O3 to α-Al2O3 at 1450 °C, e.g., the maximum shrinkage reaches 17.34% when the γ-Al2O3 to α-Al2O3 ratio is 1:2. The addition of Si–B greatly increases the low density of Al2O3 tapes due to the pores generated during the firing process of the ultrafine γ-Al2O3 powders. The sintering density increases to 97.1% when the Si–B content is 15 wt. %, and the sintering shrinkage reaches a relatively higher value of 17.25%. The obtained Al2O3-based insulating materials show a greatly co-firing matching performance with the YSZ green tapes. This work will contribute to further investigation of ceramic co-firing studies.

Damage Analysis of Urban Comprehensive Pipe Gallery Caused by Internal Gas Explosion Based on HHT

In this paper, the method of embedding piezoelectric ceramic sensors is used to test the damage of the materials and models of the urban comprehensive pipe gallery. The monitoring signal is processed by HHT method, and the frequency and energy changes of the piezoelectric signal before and after the explosion were analyzed, thus the damage characteristics of the urban comprehensive pipe gallery under the internal gas explosion are determined. The results show that in the gas explosion test inside the pipe gallery model, the waveform and peak value of the piezoelectric signal before and after the explosion did not change significantly, indicating that there was no obvious damage to the side wall of the integrated pipe gallery. However, after further time-frequency analysis of the piezoelectric signal by HHT, it is found that the dominant frequency of the piezoelectric signal after explosion has a downward trend, so it is judged that there is a small damage in the pipe gallery after explosion.

A Strain‐Temperature Integrated Polymer‐Derived SiCN Ceramic High Temperature Sensor with Wide‐Range and Ultra‐Short Response Time

AbstractFabricating strain sensors with high response in a wide temperature and strain range is still a challenge, especially in high temperature harsh environments. Herein, a dual‐functional sensor with cantilever beam structure is fabricated using polymer‐derived SiCN ceramics, which can be applied for temperature and stain monitor. The performance of the integrated sensor is evaluated from room temperature to 1000 °C and the related sensing mechanism is analyzed. The prepared strain sensor has ultrafast response of 60 ms in the strain range of 0–3500 µε and the maximum strain rate can reach 46 200 µε s−1. Moreover, the sensor has excellent stability and ultra‐high sensitivity under high temperature environments. Additionally, the temperature can be detected separately up to 1000 °C without any disturbance. This attractive integration sensor with competitive sensitivity, excellent stability, ultrafast response speed, and broad range, has great potential to detect temperature and strain signals for practical application in high temperature extreme environments.

Influence of Anodic Aluminum Oxide Nanostructures on Resistive Humidity Sensing

Humidity nanosensors play a vital role in modern technology industries, including weather forecasts, industrial manufacturing, agriculture, food and chemistry storage. In recent years, research on humidity sensors has focused on different materials such as ceramics, polymers, carbon-based materials, semiconductors, MXenes or triboelectric nanogenerators, each with their own advantages and disadvantages. Among them, anodic aluminum oxide (AAO) is a well-known ceramic humidity sensor material with a long history of research and development. AAO humidity sensors offer advantages such as simple manufacturing processes, controllable nanostructures, high thermal stability and biocompatibility. However, traditional AAO fabrication still has disadvantages like high costs and longer process times. Hence, finding a low-cost and efficient method to fabricate AAO for controlling different nanostructures to meet the requirements is consistently a major research topic. From our previous studies, we have studied the relationship between the AAO capacitive humidity sensor and its nanostructures. In this paper, we explore the effect of an AAO nanoporous structure controlled by an anodization voltage of 20–40 V on the resistive-type humidity sensor performance instead of a capacitive one. We efficiently apply one-step hybrid pulse anodization at 25 °C to significantly reduce the processing time compared to the traditional two-step process under 0–10 °C. The AAO nanostructures and their impact on sensor measurements of humidity at 20–80 RH% will be discussed in detail. An electrical resistive sensing mechanism is established for further performance improvement by controlling anodization voltage.

Piezoelectric-pneumatic material jetting printing for non-contact conformal fabrication of high-temperature thick-film sensors

Conformal printing of high-temperature thick-film sensors (TFSs) on intricate surfaces is crucial for precise integration and enhanced functionality. However, traditional contact printing faces challenges in terms of the complex motion control of 3D surfaces. With the core concept of non-contact printing, this study employs piezoelectric-pneumatic material jetting (PPMJ) to achieve rapid and uniform manufacturing of complex and multi-material conformal TFSs. PPMJ enables a wide viscosity range (50–100,000 mPa.s) and high solid content (60 wt%), accommodating various types of inks, from insulating to semiconductor materials to high-temperature alloy slurries, thus providing a broad operational window for shape control and performance modulation in the conformal manufacturing of TFSs on curved surfaces. Microscale shape control of ceramic ink features, including a parallel three-phase contact line, uniform print dimensions, and post-curing shape control, was systematically investigated. PPMJ printing facilitates the successful in situ fabrication of multi-layer TFSs, featuring the self-assembly of droplets and dependable printing consistency, with nozzle-to-substrate heights ranging from 1 to 10 mm, thus advancing the structural arrangement, design, and manufacturing of conformal multi-layer TFSs on curved surfaces. For example, the polymer-derived ceramic heat flux sensor printed by PPMJ demonstrates repeatable high-temperature responsiveness and can be integrated on the surface of turbine blades, withstanding thermal impacts from flames exceeding 800 °C. Hence, PPMJ printing technology opens new possibilities for the conformal manufacturing of various sensors on complex 3D surfaces.

Defect Detection in Grouting Sleeve Grouting Material by Piezoelectric Wave Method

The construction defects in grouting sleeves can jeopardize the safety of precast reinforced concrete structures. Thus, efficient and accurate defect detection is critical in engineering construction. In this paper, a defect detection method based on piezoelectric wave theory was proposed. Two piezoelectric ceramics were arranged within the grouting sleeve. One piezoelectric ceramic was affixed on the top of the steel bar, while the other was embedded in the grouting material, serving as the driver and sensor, respectively. The compactness defects, air cavity defects, steel anchoring defects, and water–binder ratio defects were set in the grouting sleeves, and the trends in time domain signals and signal evaluation indicators based on the wavelet packet total energy value (WPTEV) of different specimens were investigated. Based on the WPTEV, the evaluation index (EI) was proposed. In addition, the effect of the grouting material’s age on the piezoelectric wave signal was verified. Furthermore, the influence of grouting material defects on signals was simulated in ABAQUS, and the time domain signals and wavelet packet energy of sensor signals for specimens with varying defect dimensions were evaluated. The results showed that: (1) The defects in the grouting materials reduced the stress waves propagated through the grouting materials, resulting in a decrease in attenuation and an increasing trend in the signal; (2) The peak-to-peak values of piezoelectric ceramic sensors and the WPTEV of the signal increased with the degree of defects, and the WPTEV was more pronounced. For specimen M68, the WPTEV was 3.3 times that of the healthy specimen, however, the peak-to-peak value was only 2.3 times that of the healthy specimen; (3) The degree of defects was accurately determined by the defect evaluation index (EI) based on the WPTEV; (4) The signal was significantly attenuated with the increase in the age of the grouting material, especially in the first three days, and finally the signal achieved a stable value; (5) The numerical simulation indicated that the defects in the length and thickness of the air cavity in the grouting material were efficiently detected by the proposed piezoelectric arrangement in this study.

Wireless Passive Ceramic Sensor for Far-Field Temperature Measurement at High Temperatures.

A passive wireless high-temperature sensor for far-field applications was developed for stable temperature sensing up to 1000 °C. The goal is to leverage the properties of electroceramic materials, including adequate electrical conductivity, high-temperature resilience, and chemical stability in harsh environments. Initial sensors were fabricated using Ag for operation to 600 °C to achieve a baseline understanding of temperature sensing principles using patch antenna designs. Fabrication then followed with higher temperature sensors made from (In, Sn) O2 (ITO) for evaluation up to 1000 °C. A patch antenna was modeled in ANSYS HFSS to operate in a high-frequency region (2.5-3.5 GHz) within a 50 × 50 mm2 confined geometric area using characteristic material properties. The sensor was fabricated on Al2O3 using screen printing methods and then sintered at 700 °C for Ag and 1200 °C for ITO in an ambient atmosphere. Sensors were evaluated at 600 °C for Ag and 1000 °C for ITO and analyzed at set interrogating distances up to 0.75 m using ultra-wideband slot antennas to collect scattering parameters. The sensitivity (average change in resonant frequency with respect to temperature) from 50 to 1000 °C was between 22 and 62 kHz/°C which decreased as interrogating distances reached 0.75 m.

An overpressure monitoring system based on PVDF integrated Electronic sensor with enhanced noise attenuation capability

The measurement of shockwave overpressure is of great significance for the safe use of explosives. The traditional overpressure monitoring systems are based on Integrated Electronics Piezo-Electric (IEPE) ceramic sensors. However, the brittleness of piezoelectric ceramic limits the application of overpressure monitoring system in high impact overpressure testing. Herein, a novel overpressure monitoring system based on Integrated Electronic Poly (vinylidene fluoride) (PVDF) (PFIE) sensor with electromagnetic interference shielding capability and parasitic vibration noise elimination function was designed for intense overpressure acquiring. PVDF, as a polymer, can endure much higher impact pressures compared to piezoelectric ceramics. However, its larger internal resistance makes it more prone to electromagnetic interference. To address this, an electromagnetic shielding structure was designed, incorporating an impedance matching circuit that effectively reduces the sensor's output impedance. Additionally, to mitigate excessive vibration noise during overpressure testing, the differential noise reduction technique has been implemented. Both the laboratory testing and the real blast testing with 10 kg trinitrotoluene were performed to validate the PFIE overpressure monitoring system. The result shows that the electromagnetic noise suppression ability of the PFIE overpressure sensors developed for the monitoring system was improved by 45 dB, and the parasitic vibration noise could be attenuated from 30 % to 1 %, what’s more the RMS errors of the overpressure dynamic parameters obtained by the monitoring system were below 10 %. This work has successfully addressed the noise sensitivity issue inherent in PVDF when used as a pressure sensor, capitalizing on its robust impact resistance. This approach has provided a viable solution for measuring overpressure in scenarios involving intense shock pressures, leveraging the strengths of PVDF in such demanding applications.