TiO2-x films for bolometer applications: recent progress and perspectives

The bolometer is widely used in military and civilian infrared imaging due to its advantages of non-cooling, small size and portability. Thermosensitive materials seriously affect the performance of bolometers. As a kind of heat-sensitive material, the TiO2-x material has the advantages of good thermal stability, large-area preparation, and compatibility with the complementary metal-oxide semiconductor (CMOS) process. However, there is almost no review on the application of titanium oxide for bolometers. In this paper, we introduce the bolometer's main thermal and photoelectric performance parameters and the critical technologies to manufacture the bolometer. Finally, we will particularly emphasize the effects of preparation process parameters of TiO2 on the performance parameters temperature coefficient of resistance (TCR), 1/f noise, etc., were studied.

Finite element simulation of Love wave sensor for the detection of volatile organic gases

The 3D finite element (3D-FE) simulation and analysis of Love wave sensors based on PIB layers/SiO2/ST-90°X quartz structure, as well as the investigation of coupled resonance effect on the acoustic properties of the devices, are presented in this paper. The mass sensitivity of the basic Love wave device with SiO2 guiding layers solved analytically. And the highest mass sensitivity of 128 m2/kg is obtained as h s/λ =0.175. The sensitivity of the Love wave sensors for sensing VOCs is greatly improved due to the presence of coupled resonance induced by the PIB nanorods on the device surface. The frequency shifts of the sensor corresponding to CH2Cl2, CHCl3, CCl4, C2Cl4, CH3Cl and C2HCl3 with the concentration of 100 ppm are 1.431 kHz, 5.507 kHz, 13.437 kHz, 85.948 kHz, 0.127 kHz and 17.879 kHz, respectively. The viscoelasticity influence of sensitive material on the characteristics of SAW sensors is also studied. Taking account of the viscoelasticity of PIB layers, the sensitivities of SAW sensors with the PIB film and PIB nanorods decay in different degree. The gas sensing property of Love wave sensor with PIB nanorods is superior to that of the PIB films. Meanwhile, the Love wave sensors with PIB sensitive layers show good selectivity to C2Cl4, making it an ideal selection for gas sensing applications.

Studying of a sensitive material based on Ecoflex and CNTs for flexible strain sensors

Nowadays there is a great need for the development of flexible strain sensors that can register human body’s movements. In the field of wearable and smart electronics such sensors are actively being developed. Resistive-type flexible sensors are the easiest to manufacture. Their mechanism of sensitivity to deformations is based on a change in electrical resistance during deformations. In this work, we have developed the functional material for strain sensor with high tensile properties, strength and electrical conductivity. This material based on a matrix of silicone elastomer and a multi-walled carbon nanotubes (MCNTs) filler. The material showed a high elongation of 950 % with a tensile strength of 1.437 MPa. The manufacturing process included laser structuring of MCNTs to form an electrically conductive network. The linear gauge factor was 3.4, and the angular gauge factor was 0.26.

Identification of genes related to tipburn resistance in Chinese cabbage and preliminary exploration of its molecular mechanism

Background Tipburn, also known as leaf tip necrosis, is a severe issue in Chinese cabbage production. One known cause is that plants are unable to provide adequate Ca2+ to rapidly expanding leaves. Bacterial infection is also a contributing factor. Different cultivars have varying degrees of tolerance to tipburn. Two inbred lines of Chinese cabbage were employed as resources in this research. Results We determined that the inbred line ‘J39290’ was the tipburn resistant material and the inbred line ‘J95822’ was the tipburn sensitive material based on the severity of tipburn, and the integrity of cell membrane structure. Ca2+ concentration measurements revealed no significant difference in Ca2+ concentration between the two materials inner leaves. Transcriptome sequencing technology was also used to find the differentially expressed genes (DEGs) of ‘J95822’ and ‘J39290’, and there was no significant difference in the previously reported Ca2+ uptake and transport related genes in the two materials. However, it is evident through DEG screening and classification that 23 genes are highly linked to plant-pathogen interactions, and they encode three different types of proteins: CaM/CML, Rboh, and CDPK. These 23 genes mainly function through Ca2+-CaM/CML-CDPK signal pathway based on KEGG pathway analysis, protein interaction prediction, and quantitative real-time PCR (qRT-PCR) of key genes. Conclusions By analyzing the Ca2+ concentration in the above two materials, the transcription of previously reported genes related to Ca2+ uptake and transport, the functional annotation and KEGG pathway of DEGs, it was found that Ca2+ deficiency was not the main cause of tipburn in ‘J95822’, but was probably caused by bacterial infection. This study lays a theoretical foundation for exploring the molecular mechanism of resistance to tipburn in Chinese cabbage, and has important guiding significance for genetics and breeding.

Significant effect of SDS on the optimum operating temperature of ZnO nanosheets gas-sensitive materials

Many methods have been used to reduce the operational energy consumption of ZnO gas-sensitive material effectively. In this paper, different morphologies of ZnO nanomaterials are respectively prepared in the anionic hydrophilic surfactant sodium lauryl sulfate (SDS) with different concentrations as soft templates by hydrothermal method. The influence of SDS concentrations is investigated on the morphology of materials under the conditions of a weak alkali environment with the same pH, and their gas sensitivity after annealing with the same temperature and time. The morphologies and phase structures of all samples are characterized by FESEM and XRD, and their gas-sensitive properties are analyzed by CGS-1TP. Interestingly, the experimental results show that the optimal working temperature of ZnO gas-sensitive materials containing low concentration SDS is reduced by nearly 55% than that of containing 10 times this concentration, and its sensitivity is also slightly improved. The possible mechanism by which the SDS concentration affects the gas sensitivity of the material is also proposed.

Preparation of arsenene and its applications in sensors

As a family element of graphene, arsenic has attracted extensive attention due to its excellent photoelectric and transport properties. Arsenene following eight-electron coordination spontaneously forms a wavy 2-D structure, which is more stable than other 2-D materials. The adjustable band gap makes it stand out from many two-dimensional materials, and its unique semiconductor properties make it widely used in field effect transistors. In recent years, different subtypes of arsenene have been gradually discovered. Due to their special gas response characteristics, arsenene has great application potential as a gas sensitive material or resistance element in the field of sensors. Defective arsenic and arsenene modified by atoms provide more possibilities and creative solutions for gas sensing. In this paper, the properties, preparation methods and application of arsenene in sensing in recent years are reviewed. The advantages and disadvantages of arsenene are introduced, and the development prospect of arsenene is prospected.

A Study of Mechanoelectrical Transduction Behavior in Polyvinyl Chloride (PVC) Gel as Smart Sensors

Polyvinyl chloride (PVC) gels are soft electroactive polymers being researched for soft robotic applications. Sensing properties of these electroactive polymers have not been investigated in detail in regard to fundamental mechanoelectrical transduction behavior, but this smart material has been shown to exhibit a detectable response to external stimuli. This study shows PVC gels to be an extremely sensitive material when undergoing mechanoelectrical transduction and explores some response dependencies and proposes a theoretical framework for mechanoelectrical transduction within the gel. The work presented here also uncovers a very interesting phenomena under extremely low compressive loads during the initial contact with the gel. This phenomenon is attributed to a surface tension creeping motion onto the loading surface with an accompanying polarity inversion in the sensing signal relative to fully loaded gels in compression. Experimental work on hysteresis was also completed showing very little memory in steady state mechanoelectrical response to repeated stepped loading cycles. This study demonstrates the mechanoelectric ability of PVC gels to perform in sensing experiments and acts as a fundamental framework to further broaden the applications of PVC gel sensors.

Wood flooring in combination with underfloor heating systems

The main objective of the article is to inform about the wood flooring in combination with underfloor water heating systems. Wood is a very sensitive material that responds to its surroundings. For this reason, it is necessary to select a suitable wood, meeting the criteria of suitability for laying as flooring in combination with underfloor heating systems. It is also important to comply with the conditions of storage of wooden flooring and its installation under acceptable climatic conditions at the construction site, together with the technical regulations for the installation of wooden flooring in combination with underfloor heating systems, during the whole life cycle of the wood flooring. This article defines the basic input premise for the implementation of wooden floors in combination with underfloor heating systems, regarding the relevant technical standards and technological procedures valid in the Czech Republic. At the same time, the article describes possible failures of wooden floors in case of non-compliance with the above conditions. In the conclusion, we propose measures based on the described installation process failures of the wooden flooring in combination with underfloor heating systems, and after its use.