Harsh Environment Applications Research Articles

All-fiber MZI hydrostatic pressure sensor

With the rapid development of physical ocean observation, high-performance pressure sensor integrated with stable mechanical strength, sufficient pressure sensitivity as well as negligible temperature crosstalk is highly desirable but still lack of research. This paper proposes an all-fiber optical sensor based on a Mach-Zehnder interferometer (MZI) for hydrostatic pressure measurement, utilizing a multi-mode fiber (MMF)-single-hole-dual-core fiber (SHDCF)-MMF structure. The MMF sections act as a beam splitter and coupler to enhance the Mach-Zehnder interference. The SHDCF serves as the pressure-sensing section. Under the action of the enclosed air hole in SHDCF, hydraulic variations cause changes in the structural parameters of the fiber, especially the refractive index change caused by the elasto-optical effect, which leads to the shift of the interference dips. The experimental results prove that the SHDCF-based MZI sensor has a higher hydrostatic pressure sensitivity than other hole-less silica fiber-based sensors. The max pressure sensitivity is −0.2358 nm/MPa in the range of 0.1 MPa to 16.1 MPa with good linearity and reliability. Moreover, the low temperature–pressure cross-sensitivity of 0.04368 MPa/℃ also proves our sensor more competitive in harsh environment applications.

A Flexible Self-Powered Noncontact Sensor with an Ultrawide Sensing Range for Human-Machine Interactions in Harsh Environments.

Noncontact human-machine interactions (HMIs) provide a hygienic and intelligent approach to communicate between humans and machines. However, current noncontact HMIs are generally hampered by the interaction distance, and they lack the adaptability to environmental interference such as high humidity conditions. Here, we explore a self-powered electret-based noncontact sensor (ENS) with moisture-resisting ability and ultrawide sensing range exceeding 2.5 m. A megascopic air-bubble structure is designed to enhance charge-storage stability and charge-recovery ability of the ENS based on the heterocharge-synergy effect in electrets. Besides, multilayer electret films are introduced to strengthen the electric field by utilizing the electrostatic field superposition effect. Thanks to the above improved performances of the ENS, we demonstrate various noncontact HMI applications in harsh environments, including noncontact appliances, a moving trajectory and accidental fall tracking system, and a real-time machine learning-assisted gesture recognition system with accuracy as high as 99.21%. This research expands the way for noncontact sensor design and may further broaden applications in noncontact HMIs.

Radiation stability of electron beam irradiated high degree sulfonated poly(ether ether ketone) membranes for the applications in nuclear facilities

Sulfonated poly(ether ether ketones) (SPEEK) have raised interest as a replacement of Nafion® proton exchange membranes (PEM) for the application in harsh environments involving material exposure to ionizing radiation, for example, radioactive hydrogen isotope separation from water. This study is dedicated to evaluate the effects of high dose (500 kGy) electron beam irradiation on the physico-chemical and thermomechanical properties of highly sulfonated (degree of sulfonation 60–90 %) SPEEK membranes irradiated in air and water. Spectrometric and thermogravimetric analysis indicated slight changes in the material properties after irradiation with increase of the degree of sulfonation (DS). Tensile tests and thermomechanical analysis of irradiated samples indicated notable deterioration of properties at higher DS values. Results demonstrate that SPEEK membranes with DS around 70 % could be a replacement of the traditional PEM for the applications where exposure to ionizing radiation occurs.

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.

Total ionizing dose and single event effect response of 22 nm ultra-thin body and buried oxide fully depleted silicon-on-insulator technology

The test chip including transistors and Static Random Access Memory (SRAM) is proposed and fabricated by an advanced 22 nm Ultra-Thin Body and Buried Oxide Fully Depleted Silicon-on-Insulator (UTBB FD-SOI) technology. Experimental results of Co-60 irradiation and heavy ion experiments are presented. Total Ionizing Dose (TID) experiment results show that the threshold voltage shift of the transistor is about 100 mV when the dose is 500 krad(Si) and the SRAM irradiated to a dose of at least 300 krad(Si) can maintain its functionality, which means that 22 nm UTBB FD-SOI devices exhibit significantly improved total dose tolerance performance compared to the previous generation process. TID-induced threshold voltage shift in conventional-well nMOSFET can be mitigated by applying biasing to back-gate, while back-gate biasing is invalid for TID mitigation of the conventional-well pMOSFET. Heavy ion experimental results make known that 22 nm UTBB FD-SOI technology has contributions to Single Event Effect (SEE) hardness and the hardened SRAM has higher single event upset (SEU) tolerance and even SEU immunity. The research indicates that the circuits manufactured by 22 nm UTBB FD-SOI technology have great potential space applications in harsh radiation environments.

The benefits of multi-constellation GNSS for cadastral positioning applications in harsh environments

The benefits of multi-constellation GNSS for cadastral positioning applications in harsh environments

Achieving broadband electromagnetic absorption at a wide temperature range up to 1273 K by metamaterial design on polymer-derived SiC-BN@CNT ceramic composites

High-temperature broadband electromagnetic wave (EMW) absorption has emerged as a forefront challenge of EMW functional materials for harsh environment applications such as aerodynamically heated parts of stealth aircraft and aero engines. Herein, an innovative strategy for broadband absorption at high temperatures is proposed by combining the microstructural design of the EMW absorption phase in the polymer-derived SiC with a periodic structure design. The metamaterial was designed on SiC-BN@CNT ceramic composites with the shape of a frustum pyramid. The experimental results reveal that SiC-BN@CNT metamaterials exhibit excellent absorption performance even under a high-temperature environment of 1273 K, in which the effective absorption bandwidth (EAB) (below −10 dB) can achieve 15.52 GHz, almost covering the whole S, C, X, and Ku bands. Moreover, the CST simulation results show that the SiC-BN@CNT metamaterials have an impressive EAB of 34.62 GHz and the average absorption intensity is remarkably high with a value of 21.07 dB (<99 % absorption) in the frequency range of 2–40 GHz. The exciting EMW attenuation capability is ascribed to favorable impedance matching, enhanced conduction loss abilities, and multiple polarization loss at high temperatures. This work provides valuable insights for the development of broadband-absorbing material in high-temperature harsh environments.

A phase transformation–phosphorescence model of europium-doped yttria-stabilized zirconia and its application in two-dimensional thermal history measurement

Phosphorescence thermal history sensors are off-line temperature measurement devices with potential applications in harsh environments. However, changes in phosphorescence after heating at various temperatures or for various durations cannot be precisely quantified based on current theory. In this study, europium-doped yttria-stabilized zirconia (YSZ:Eu) was selected as a potential thermal history sensor and its structural and phosphorescence properties were characterized after heating at various temperatures. It was found that the tetragonal-to-cubic phase transformation of zirconia had a major effect on the phosphorescence intensity ratio (PIR) of YSZ:Eu. Accordingly, theoretical and semi-empirical versions of a novel phase transformation–phosphorescence model were developed based on Judd–Ofelt theory and the Avrami equation, and were used to quantify phosphorescence changes induced by heating YSZ:Eu at various temperatures and for various durations. The results of a calibration experiment showed that the PIR increased from 0.5 to 1.0 as the heating temperature and heating duration increased from 900 °C to 1200 °C and from 10 min to 80 min, respectively. The mean relative fitting errors of the theoretical and semi-empirical model were 2.2 % and 5.6 %, respectively. Finally, thermal history measurement was demonstrated in a flame-impingement experiment that was conducted using a phosphor-coated plate subjected to two different heating durations. The phosphorescence signals collected by an industrial camera were processed to yield two-dimensional (2D) surface-temperature distributions of the plate and compared with those obtained using an infrared camera. The average differences between the 2D surface-temperature distributions obtained by the two methods were 5.9 °C and 6.5 °C for 40 min and 80 min heating durations, respectively. These findings enhance theoretical understanding of thermal history sensing and will facilitate advancement from single-point to 2D thermal history measurement.

Pt/HTCC Alumina based Electronic Packaging System and Integration Processes for High Temperature Harsh Environment Applications

Electronic devices capable of operation at 500°C are required for long term Venus surface missions, as well as for in situ monitoring and control of next generation aeronautical engines. High temperature sensors and electronics can also find many applications in military, and energy and automobile industries. Various silicon carbide (SiC) sensors and electronic devices have been developed for operation at 500 °C, and a compatible packaging system is needed for long term test and deployment of these high temperature devices. High temperature co-fired ceramics (HTCC) alumina with platinum (Pt) conductor was proposed for high temperature electronic packaging. A prototype Pt/HTCC alumina packaging system including chip-level package and circuit board has been briefly reported previously for long-term electrical testing of SiC integrated circuits at 500 °C, and brief testing at much higher temperatures. HTCC alumina is an excellent dielectric material with acceptable dielectric constant and low dielectric loss over wide temperature and frequency ranges. Pt is chemically noble and can be co-fired with HTCC alumina in air ambient producing a viable electronic packaging material system for high temperature applications. This paper presents a more detailed description of this packaging system including prototype low power packages and circuit boards based on HTCC alumina and Pt metallization for 500°C and other harsh environment applications. The key technical considerations for chip-level packaging and circuit board assembly, including materials and processes for 500 °C durable wire-bonding and SiC die attach, and integration of multi-chip circuit boards, are presented. Experimental test results of this packaging approach applied to SiC integrated circuits at 500 °C and 700°C are discussed as well.

Improved dielectric and energy storage properties of three‐dimensional BaTiO3/polyvinyl alcohol‐boron nitride flexible dielectric composite via template infiltration strategy

AbstractContinuous three‐dimensional BaTiO3 (3DBT) ceramic network was prepared by the sol‐gel method using cleanroom wipers as the template. Subsequently, flexible 3DBT/polyvinyl alcohol‐boron nitride nanosheets (PVA‐BNNS) composite dielectric films were facilely fabricated by inversely introducing different BNNS concentrations of PVA‐BNNS solution into the 3DBT network. The results demonstrated that PVA solution effectively embedded into the 3DBT framework through an inverse infiltration process, thereby endowing the material with excellent flexibility. The content of 3DBT in the saturated 3DBT/PVA‐BNNS composite was ∼27 wt% (6.9 vol%). In addition, the 3DBT/PVA‐1.0%BNNS system exhibited an excellent dielectric constant of 17.4 (at 1 kHz), a high breakdown strength of 114.5 kV·mm−1 and an energy density of 2.51 J·cm−3 (at 110 kV·mm−1), being 1.67, 1.58 and 7.17 times higher than those of traditional fabricated 27 wt% nano‐BT/PVA (at 70 kV·mm−1) composite, respectively. What's more, the obtained 3DBT/PVA‐BNNS dielectric film exhibited superior thermal and mechanical stability, indicating potential applications in harsh environments.

Investigation of Ultra-High-Temperature Sapphire-Based RF Passive Sensor for Harsh Environment Applications

Investigation of Ultra-High-Temperature Sapphire-Based RF Passive Sensor for Harsh Environment Applications

Highly Flexible and Acid-Alkali Resistant TiN Nanomesh Transparent Electrodes for Next-Generation Optoelectronic Devices.

Transparent electrodes are vital for optoelectronic devices, but their development has been constrained by the limitations of existing materials such as indium tin oxide (ITO) and newer alternatives. All face issues of robustness, flexibility, conductivity, and stability in harsh environments. Addressing this challenge, we developed a flexible, low-cost titanium nitride (TiN) nanomesh transparent electrode showcasing exceptional acid-alkali resistance. The TiN nanomesh electrode, created by depositing a TiN coating on a naturally cracked gel film substrate via a sputtering method, maintains a stable electrical performance through thousands of bending cycles. It exhibits outstanding chemical stability, resisting strong acid and alkali corrosion, which is a key hurdle for current electrodes when in contact with acidic/alkaline materials and solvents during device fabrication. This, coupled with superior light transmission and conductivity (88% at 550 nm with a sheet resistance of ∼200 Ω/sq), challenges the reliance on conventional materials. Our TiN nanomesh electrode, successfully applied in electric heaters and electrically controlled thermochromic devices, offers broad potential beyond harsh environment applications. It enables alternative possibilities for the design and fabrication of future optoelectronics for advancements in this pivotal field.

Hollow silicon carbide microspheres for excellent and lightweight electromagnetic wave absorber

Developing semiconductor ceramic materials with lightweight, outstanding stability, and high-performance electromagnetic wave (EMW) absorption are attractive for harsh environments. Due to thermal and chemical stability, designable microstructure, and tunable dielectric property, microstructured silicon carbide (SiC) ceramics offer promising potential as excellent EMW absorbers while limited by the scarce fabricating methods. Here, a simple coaxial electrospinning technology and the high-temperature calcination process are developed for the first time to fabricate hollow SiC microspheres (HSCMs) for EMW absorbers. Owing to the sizeable SiC-free space interface in the shell and internal void, the inner hollow structure also endows HSCMs with excellent EMW absorbing properties. By comparing with the composite of 40 wt% solid SiC microspheres (SSCMs)/paraffine, it is found that the 40 wt% HSCMs/paraffin composite exhibits superior dielectric properties and a minimum reflection loss (RL) value of − 61.6 dB at 7.7 GHz and 3.4 mm thickness, associated with the most considerable adequate absorption bandwidth of 4.9 GHz (from 12.6 to 17.5 GHz) at 1.9 mm thickness. This work gives rise to a handy method for fabricating hollow SiC with lightweight and high-efficiency EMW absorption. It will potentially boost the development of next-generation EMW absorbers for harsh environment applications.

Experimental–Simulation Analysis of a Radiation Tolerant Erbium-Doped Fiber Amplifier for Space Applications

Research on optical amplifiers has highlighted how ionizing radiation negatively impacts the performance of erbium-doped fiber amplifiers (EDFAs), through the degradation of their gain. The amplitudes and kinetics of this degradation are mainly explained by the radiation-induced attenuation (RIA) phenomenon at the pump and signal wavelengths. In this work, the gain degradation of a radiation tolerant EDFA (exploiting a cerium-co-doped active optical fiber) induced by ionizing radiation up to 3 kGy (SiO2), at two dose rates, 0.28 Gy/s and 0.093 Gy/s, is studied through an experimental/simulation approach. Using a home-made simulation code based on the rate and power propagation equations and including the RIA effects, the radiation-dependent performance of EDFAs were estimated. The variations in the spectroscopic parameters caused by irradiation were also characterized, but our results show that they give rise to EDFA gain degradation of about 1%. To overcome the issue of overestimating the RIA during the radiation tests on the sole active rare-earth-doped fiber, a new RIA experimental setup is introduced allowing us to better consider the photobleaching mechanisms related to the pumping at 980 nm. A good agreement between experimental and simulated gain degradation dose dependences was obtained for two different irradiation conditions, thus also validating the simulation code for harsh environments applications.

Corrosion-resistant L12-strengthened high-entropy alloy with high strength and large ductility

Corrosion-resistant alloys with high strength and large ductility are desirable for applications in harsh environments where high structural load-carrying capacity is required. In this work, we designed an L12-strengthened high-entropy alloy (HEA) of composition (NiCo)77Cr13Al5Nb5 (at.%) that combines excellent mechanical properties and good corrosion resistance. The formation of a thin passive film of non-stoichiometric compounds with an amorphous structure, characterized by an enrichment of Cr2O3 and Nb2O5, contributes to the superior localized corrosion resistance. The precipitation strengthening brought about by coherent L12 particles and the multi-stage plastic deformation dominated by stacking faults (SFs) provides ultrahigh strength and appreciable ductility, respectively.

Achieving Superior Corrosion Resistance of TiB2 Reinforced Al-Zn-Mg-Cu Composites via Optimizing Particle Distribution and Anodic Oxidation Time

In this study, the effects of particle distribution and anodizing time on the microstructure and corrosion resistance of the TiB2 particle-reinforced Al-Zn-Mg-Cu composite were investigated. Relationships between TiB2 particle distribution, anodizing time, coating growth rule, and corrosion resistance were characterized and discussed using an optical microscope, a scanning electron microscope, an electrochemical test, and a salt spray test. Dispersion of TiB2 particles by powder metallurgy improved the corrosion resistance of the anodized coating on composites. Compared with the matrix, the corrosion potential (Ecorr) of the anodized coating shifted to the positive direction, and the corrosion current density (icorr) decreased. Meanwhile, the icorr of the coating decreased initially and then increased with the extension of the anodization time. The corrosion resistance of the coating was optimal at an anodization time of 20 min. The corrosion resistance of the composite was determined by both the porosity and thickness of the coating. Additionally, all samples treated by potassium dichromate sealing had no corrosion points after a 336-h salt spray test, demonstrating an excellent corrosion resistance suitable for harsh environmental applications in industry.

Low-cost, superhydrophobic, flame-retardant sunflower straw-based xerogel as thermal insulation materials for energy-efficient buildings

Low cost, low energy consumption, and environment-friendly novel thermal insulation materials are highly attractive for energy-efficient buildings. However, traditional petroleum-based foams and aerogel require complicated processing, high cost, and non-degradability, which limit their sustainable development and application. Herein, multifunctional robust sunflower straw-based xerogels as thermal insulation materials are fabricated by simply filtrating and drying under ambient pressure without any extraction processing, due to sunflower straw raw materials with high content of cellulose. With the addition of KH550 and SiO2 nanoparticles, the obtained sunflower straw-based xerogels exhibit excellent thermal insulation (0.0469 W/(mK)), superior superhydrophobicity (water contact angle (WCA) = 153.2°), remarkable fire resistance, high mechanical property. These advanced properties make it an ideal thermally insulation material for diversified applications in harsh environments.

Durability improvement mechanism of polymer cement protective coating based on functionalized MXene nanosheets modified polyacrylate emulsion

Polymer cement coatings (PCCs) have a wide range of applications in the field of concrete protection. Excellent durability of the PCCs is extremely essential for protecting the concrete in long-time service life. However, one of the most popular polymer emulsion, polyacrylate based cement coatings show insufficient durability and restrict their wide application in complicated and harsh environment. In this study, the novel two-dimensional nanomaterial MXene was incorporated to PCCs for improving the durability of the PCCs, the MXene was functinalized by vinyl triethylsilane (VTEO) (V-MXene) followed by in-situ seed emulsion polymerization method to synthesize the V-MXene modified polyacrylate emulsion. The effects of V-MXene incorporation on the rheological property, mechanical properties, bonding strength, UV aging resistance, saltwater immersion resistance, thermal aging resistance of PCCs were systematically investigated and the durability improvement mechanism was revealed. When the V-MXene dosage is 0.15 wt%, the tensile strength and bonding strength of the PCCs increased by 28.76 % and 30.84 % as compared with the blank samples, respectively. The introduction of V-MXene to PCCs can remarkably improve the UV aging resistance, saltwater immersion resistance, heat resistance. The V-MXene can decrease the UV radiation energy absorbed into the PCCs, and can create a “labyrinth effect”, prolonging the penetration path of water and corrosion ions. The V-MXene can also enhance the cross-linking density of the polymer phase combined with organic and inorganic interpenetrating networks, thereby enhancing the thermal stability of PCCs. This research provides a feasible strategy for the fabrication of high performance PCCs with excellent durability.

Ruggedized sensor packaging with advanced die attach and encapsulation material for harsh environment

Current gas sensors are typically graded for performance up to 100 °C and limited by the materials used in their packaging. This work aims to select, design and investigate novel materials for die attach and encapsulation technology, such as copper nanoparticles-based die attach and phthalonitrile-based encapsulant, for the fabrication of a packaged gas sensor for harsh environment applications. This is done through a series of test protocols and reliability assessments developed to simulate operations at high temperature and under strong vibration.

Robust covalent organic frameworks membranes for ultrafast dye/salt separation in harsh environments

Although covalent organic frameworks (COFs) membranes have promising applications in water treatment due to their ordered structure and adjustable pore size, most of them are imine-linked ones, which severely limits their application in harsh environments. Herein, we offer a stable novel COFs membrane which is composed of hydrazone bonds and β-ketoenamine structures. Such β-ketoenamine based COFs composite membrane was fabricated via interfacial catalytic polymerization on a nylon substrate, which was generated at the water (P-Toluenesulfonic acid)/n-hexane (2,5-dimethoxyterephthalhydrazide, 1,3,5-triformylphoroglucinol) interface. The resultant COFs membrane demonstrates excellent chemical stability in strong acidic (2 mol/L)/alkaline (9 mol/L)/organic solvents (dioxane, acetone, methanol, and ethanol) media. The optimized COFs membrane achieved 109.73 L m−2 h−1 bar−1 permeance in Congo Red aqueous solution and 99.56 % CR rejection. This study exploits a novel approach to produce robust COFs membranes under extreme conditions.