Article
Chemistry, Analytical
LiangLiang Liu, Serhiy Korposh, David Gomez, Ricardo Correia, Barrie R. Hayes-Gill, Stephen P. Morgan
Summary: This work presents a functionalized optical fibre probe with 'cotton-shaped' gold-silica nanostructures for monitoring relative humidity (RH). The sensor utilizes the localized surface plasmon resonance (LSPR) of self-assembled nanostructures and demonstrates a high sensitivity to RH after optimization. The plasmonic hybridization mode sensor exhibited excellent linearity, reversibility, and fast response and recovery times.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Chemistry, Multidisciplinary
Ming Hui Chua, Xiang Yun Debbie Soo, Kang Le Osmund Chin, Zhuang Mao Png, Qiang Zhu, Jianwei Xu
Summary: Hydrochromic materials can undergo color changes in response to water and moisture, which can be modulated by controlling the composition and structure of the cations. This study proposes a hydrochromic mechanism involving xanthylium cations and demonstrates the potential application of this system in smart packaging.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Engineering, Multidisciplinary
Xin Cheng, Junhui Hu, Kun Zhu, Zhiyong Zhao
Summary: The study introduces a high-resolution POF-based humidity sensor utilizing microwave photonic interrogation technique, achieving a sensitivity of 84 MHz/RH% and a resolution of 0.0119 RH%. By converting humidity changes into frequency shifts of the RF filter's passband, the sensor is capable of detecting humidity with high precision.
Article
Chemistry, Analytical
Chenyang He, Serhiy Korposh, Ricardo Correia, Liangliang Liu, Barrie R. Hayes-Gill, Stephen P. Morgan
Summary: The optical fibre sensor developed can measure relative humidity and temperature simultaneously, with high sensitivity and low crosstalk, and a fast response time. Compared to traditional grating based optical fibre sensors, this sensor is more cost-effective and simpler to manufacture, showing great potential for widespread use in healthcare applications.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Multidisciplinary
Ming Hui Chua, Xiang Yun Debbie Soo, Wei Peng Goh, Zhuang Mao Png, Qiang Zhu, Jianwei Xu
Summary: This research presents a new hydrochromic system using thioxanthene-9-ols and thioxanthylium cations. The color change between thioxanthene-9-ol and its cation species is highly reversible, allowing for multiple activation-deactivation cycles. The color and moisture-sensitivity of the thioxanthylium cations can be tuned by functionalizing the thioxanthene core. This system shows potential applications in humidity sensing and anti-counterfeiting, as demonstrated by paper probes.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Engineering, Electrical & Electronic
Burcu Arman Kuzubasoglu
Summary: This study reviews a variety of humidity measurement instruments made of different materials and operating on different principles that are currently available. It also discusses the classification methods for these instruments based on their working principles. The study further explores the commonly used designs for flexible humidity sensors, humidity-sensitive materials, sensing mechanisms, major properties of humidity sensors, and the influence of temperature on humidity sensors. Additionally, it provides an overview of current research in this area, as well as the existing challenges.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Analytical
Zhiyan Ma, Teng Fei, Tong Zhang
Summary: Humidity is a physical quantity that measures the concentration of water vapor in the air. Humidity sensors are widely used in various fields due to their advantages of portability, easy fabrication, low cost, high sensitivity, and fast response. However, developing high-performance low humidity sensors still faces challenges due to the small amount of water molecules they can adsorb and the limitations of harsh environments. This paper reviews the research progress of low humidity sensors for nearly three decades, including the necessity of low humidity detection, measurement methods, and different types of sensors.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Engineering, Electrical & Electronic
LiangLiang Liu, Zijuan Tang, Chenyang He, Serhiy Korposh, Shuqin Lou, Stephen P. Morgan
Summary: The optical fibre ammonia gas sensor demonstrated in the study utilizes a functionalized suspended-core fibre and a ratiometric method for signal processing, showing a capability of detecting ammonia at ppb levels with a fast response time and reusability after treatment.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Shailesh Kumar, Kuldeep Kumar Raina, Tarikul Islam
Summary: A capacitive humidity sensor for online monitoring of transformer moisture was developed in this study, with sensitivity optimized by controlling the pore morphology of a nano structured thin film of Al2O3. The sensor's responses were tested under varying humidity conditions and compared between different development conditions. The sensor showed sensitivity for detecting moisture in the range of 180 ppm to 1000 ppm, and corrective action based on its response can improve the long-term condition of the transformer.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Green & Sustainable Science & Technology
Bharathi Raju, R. Kumar, M. Senthilkumar, Riza Sulaiman, Nazri Kama, Samiappan Dhanalakshmi
Summary: Humidity is an important factor that enhances biogenic acidic corrosion in concrete structures of sewers. This study proposes an optical humidity sensor for deployment in harsh environments like sewer structures, which shows good sensitivity and other evaluation metrics.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Chemistry, Analytical
Adam C. Funnell, Peter James Thomas
Summary: This paper presents a flexible weight sensor that utilizes optical fibre macrobending loss with 1550 nm wavelength light and small fibre bending path lengths. An applied load on the sensor causes a increase in the optical loss of the fibre, which is achieved by depressing an impactor layer of cylindrical protrusions into a soft mat covered with optical fibre. Experimental study shows the effect of different fiber types, impactor materials, impactor designs, and protrusion bend radii on the optical loss.
Article
Polymer Science
Xin Lu, Konstantin Hicke, Mathias Breithaupt, Christoph Strangfeld
Summary: This study presents a preliminary investigation on distributed humidity monitoring during the drying process of concrete using embedded polymer optical fiber (POF). Experimental results indicate that the signal received at 650 nm increases, while the fiber attenuation factor at 500 nm clearly increases, which is consistent with the measurement result of the electrical humidity sensors embedded in the concrete sample.
Article
Chemistry, Analytical
Katerina Lazarova, Silvia Bozhilova, Sijka Ivanova, Darinka Christova, Tsvetanka Babeva
Summary: Thin spin-coated polymer films of amphiphilic copolymer obtained by partial acetalization of poly(vinyl alcohol) are used as humidity-sensitive media for flexible humidity sensor applications. Pre-metallization of the substrate is implemented to increase the optical contrast and sensitivity of the sensor. The sensing behavior is evaluated by monitoring transmittance values at different humidity levels, and the sensor's hysteresis and sensitivity are determined after bending deformations. The successful development of a flexible sensor for optical monitoring of humidity in a wide range is demonstrated and discussed.
Article
Chemistry, Analytical
Xing Rao, Lin Zhao, Lukui Xu, Yuhang Wang, Kuan Liu, Ying Wang, George Y. Chen, Tongyu Liu, Yiping Wang
Summary: Optical humidity sensors have evolved over decades by utilizing a variety of optical fibers and functional materials, along with different sensing mechanisms and optical techniques. This review aims to cover the majority of optical humidity sensors, highlight design and performance trends, and discuss challenges in various applications.
Article
Construction & Building Technology
A. Romano, S. Grammatikos, M. Riley, A. Bras
Summary: This study focuses on the specific heat capacity of bio-based earth mortars at different relative humidities, finding that the fiber content can affect the thermal performance of the mortars. Experimental results indicate that the specific heat capacity of mortars with sheep wool and saw mill residue varies significantly at different relative humidities.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Jan Werner, Mathias Belz, Karl-Friedrich Klein, Tong Sun, K. T. Grattan
Summary: The detection of O2 using optical techniques is important and significant progress has been made in this area. A new sensor has been developed with a specially-formed tip design, showing extreme fast response times and stable performance.
Article
Engineering, Electrical & Electronic
Mohamad Ashraff Alias, Harith Ahmad, Muhamad Zharif Samion, Muhammad Syamil Mohd Sa'ad, Lim Kok Sing, Kenneth T. V. Grattan, B. M. Azizur Rahman, Gilberto Brambilla, Muhammad Khairol Annuar Zaini, Leonard Bayang, Mohammad Faizal Ismail
Summary: A new design of optical Fiber Bragg Grating (FBG)-based sensor for torsion measurement has been developed using 3D printing technology. The sensor demonstrates high accuracy and sensitivity, and can compensate for temperature changes. It has the potential for wide application in engineering.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Optics
Guangdong Song, Shengen Zhu, Wenhao Zhang, Binxin Hu, Feng Zhu, Hua Zhang, Tong Sun, Kenneth T. Grattan
Summary: In this work, an investigation of the combination of laser-induced breakdown spectroscopy (LIBS) and one-dimensional convolutional neural networks (1DCNNs) is presented for automated rock classification and improved classification accuracy. An improved Bayesian optimization (BO) algorithm is proposed and applied to automatic rock classification using LIBS and 1DCNN, leading to a reduction in modeling time by about 65%, and achieving 99.33% and 99.00% accuracy for the validation and test sets of 1DCNN.
Article
Engineering, Multidisciplinary
Leifeng Zhang, Changle Li, Huijuan Dong, Xiaojing Liu, Tong Sun, Kenneth T. V. Grattan, Jie Zhao
Summary: Shape sensing is important for manipulating flexible needles. This study designed a 0.6 mm diameter stylet with Fiber Bragg Gratings (FBGs) and integrated a gradient-based optimization method for shape sensing, achieving low measurement errors.
Article
Engineering, Electrical & Electronic
M. S. M. Sa'ad, H. Ahmad, M. A. Alias, M. K. A. Zaini, K. S. Lim, S. W. Harun, K. T. V. Grattan, B. M. A. Rahman, G. Brambilla, S. A. Reduan, L. Bayang, M. F. Ismail
Summary: This article introduces a surface-mounted tilt sensor that is designed to measure the inclination angle of engineered structures or slopes in two directions. The sensor utilizes strain-sensitive fiber Bragg gratings (FBGs) for tilt angle measurement bidirectionally and uses a strain-free FBG for temperature compensation. The compact, robust, and easy-to-install tilt sensor shows excellent potential for various geotechnical applications, mainly in landslide detections, ground movement, and engineered slope monitoring, as supported by laboratory calibration and field test data.
IEEE SENSORS JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Chunhua Qin, Yiyuan Wang, Ziying Liu, Wenjia Li, Yuxiang Li, Ping Li, Zheng Zhu, Chunying Guan, Jinhui Shi, Kenneth T. V. Grattan
Summary: In this study, a miniaturized high-efficiency polarizer based on an Au-on-silica grating structure has been proposed, which can cover the entire visible and near-infrared spectral ranges with an extinction ratio (ER) of 60 dB in this range. By regulating the thickness of the grating, an ER of up to 150 dB can be achieved. By integrating this high-performance polarizer with an optical fiber meta-tip, a refractive polarizer with an ER value of >45 dB over the entire spectral range has been demonstrated.
Article
Multidisciplinary Sciences
Tianlong Li, Shimin Yu, Bei Sun, Yilong Li, Xinlong Wang, Yunlu Pan, Chunlei Song, Yukun Ren, Zhanxiang Zhang, Kenneth T. V. Grattan, Zhiguang Wu, Jie Zhao
Summary: Swimming microrobots guided in the circulation system have great potential in precision medicine. A new design of swimming microrobots with clawed geometry, red blood cell (RBC) membrane-camouflaged surface, and magnetically actuated retention is discussed. The microrobots showed effective magnetic propulsion and active retention even against a flow of 2.1 cm/s, indicating promising biomedical applications.
Article
Engineering, Electrical & Electronic
Yunqing Guan, Ting Zhang, Xiaopeng Dong, Tong Sun, Kenneth Thomas Victor Grattan
Summary: This article presents a compact fiber-optic sensor based on a fiber Bragg grating (FBG), partially bonded with thick polyimide (PI) films, for the simultaneous measurement of humidity and temperature. The proposed sensing structure with PI films enhances the sensor response to both humidity and temperature significantly.
IEEE SENSORS JOURNAL
(2023)
Article
Automation & Control Systems
Jie Zhao, Guanyu Mu, Huijuan Dong, Tong Sun, Kenneth Thomas Victor Grattan
Summary: Self-running piezoelectric robots have the advantages of being low cost, high load ratio, fast speed of operation, and few limitations in confined spaces or for underwater applications. A novel standing wave ratio (SWR)-based control method, using the adjustment of the temporal phase shift, ? has been derived and demonstrated to achieve smoother motion and higher resolution of the motion speed. Through a series of experiments, the motion characteristics of the robot, such as voltage-speed, load capacity, and ability to move on different surface materials, have been tested and reported.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Automation & Control Systems
Huijuan Dong, Mingyang Sui, Guanyu Mu, Jie Zhao, Tianlong Li, Tong Sun, Kenneth T. V. Grattan
Summary: This article discusses the use of surface acoustic wave (SAW) technology in lab-on-a-chip applications for droplet actuation. By adjusting the excitation phase shift, theta, of interdigital transducers (IDTs), the velocity and direction of microdroplets can be controlled. The authors present the equation for the vibration of mixed traveling surface acoustic waves (TSAWs) and standing surface acoustic waves (SSAWs) formed on the substrate surface operating in the exciter-exciter mode. They derive an analytical expression for the acoustic standing wave ratio as a function of theta and the spatial phase difference. Experimental results demonstrate the potential of the exciter-exciter mode in increasing the velocity of actuated droplets compared to the traditional exciter-absorber mode.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Engineering, Electrical & Electronic
Hanqi Zhang, Qi Wu, Xiangrong Su, Jun Guo, Ke Xiong, Tong Sun, Kenneth T. V. Grattan
Summary: A cantilevered microfiber Bragg grating (CMFBG) sensor with high sensitivity and resonant frequency has been proposed and demonstrated. The CMFBG design allows for the reception of ultrasonic guided waves and the formation of standing waves, resulting in significant signal amplitude enhancements compared to conventional fiber Bragg gratings. The geometric parameters of the CMFBG design have been found to influence the ultrasonic sensitivity and resonant frequencies observed.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Biochemical Research Methods
Mingyang Sui, Huijuan Dong, Guanyu Mu, Jingze Xia, Jie Zhao, Zhen Yang, Tianlong Li, Tong Sun, Kenneth T. Grattan
Summary: This study proposes a method of manipulating droplets by changing the excitation parameter, which allows for adjustment of droplet velocity and direction, as well as significant improvement in droplet velocity. This alternative approach provides a new method for droplet manipulation in 'lab-on-a-chip' applications.
Article
Engineering, Multidisciplinary
Sicheng Jiao, Shixiang Wang, Minge Gao, Min Xu
Summary: This paper presents a non-contact method of thickness measurement for thin-walled rotary shell parts based on a chromatic confocal sensor. The method involves using a flip method to obtain surface profiles from both sides of the workpiece, measuring the decentration and tilt errors of the workpiece using a centering system, establishing a unified reference coordinate system, reconstructing the external and internal surface profiles, and calculating the thickness. Experimental results show that the method can accurately measure the thickness of a sapphire spherical shell workpiece and is consistent with measurements of other materials.
Article
Engineering, Multidisciplinary
Rajeev Kumar, Sajal Agarwal, Sarika Pal, Alka Verma, Yogendra Kumar Prajapati
Summary: This study evaluated the performance of a CaF2-Ag-MXene-based surface plasmon resonance (SPR) sensor at different wavelengths. The results showed that the sensor achieved the maximum sensitivity at a wavelength of 532 nm, and higher sensitivities were obtained at shorter wavelengths at the expense of detection accuracy.
Article
Engineering, Multidisciplinary
Attilio Di Nisio, Gregorio Andria, Francesco Adamo, Daniel Lotano, Filippo Attivissimo
Summary: Capacitive sensing is a widely used technique for a variety of applications, including avionics. However, current industry standard Capacitive Level Sensors (CLSs) used in helicopters perform poorly in terms of sensitivity and dynamic characteristics. In this study, novel geometries were explored and three prototypes were built and tested. Experimental validation showed that the new design featuring a helicoidal slit along the external electrode of the cylindrical probe improved sensitivity, response time, and linearity.
Article
Engineering, Multidisciplinary
Kai Yang, Huiqin Wang, Ke Wang, Fengchen Chen
Summary: This paper proposes an effective measurement method for dynamic compaction construction based on time series model, which enables real-time monitoring and measurement of anomalies and important construction parameters through simulating motion state transformation and running time estimation.
Article
Engineering, Multidisciplinary
Hui Fu, Qinghua Song, Jixiang Gong, Liping Jiang, Zhanqiang Liu, Qiang Luan, Hongsheng Wang
Summary: An automatic detection and pixel-level quantification model based on joint Mask R-CNN and TransUNet is developed to accurately evaluate microcrack damage on the grinding surfaces of engineering ceramics. The model is effectively trained on actual micrograph image dataset using a joint training strategy. The proposed model achieves reliable automatic detection and fine segmentation of microcracks, and a skeleton-based quantification model is also proposed to provide comprehensive and precise measurements of microcrack size.
Review
Engineering, Multidisciplinary
Sang Yeob Kim, Da Yun Kwon, Arum Jang, Young K. Ju, Jong-Sub Lee, Seungkwan Hong
Summary: This paper reviews the categorization and applications of UAV sensors in forensic engineering, with a focus on geotechnical, structural, and water infrastructure fields. It discusses the advantages and disadvantages of sensors with different wavelengths and addresses the challenges of current UAV technology and recommendations for further research in forensic engineering.
Article
Engineering, Multidisciplinary
Anton Nunez-Seoane, Joaquin Martinez-Sanchez, Erik Rua, Pedro Arias
Summary: This article compares the use of Mobile Laser Scanners (MLS) and Aerial Laser Scanners (ALS) for digitizing the road environment and detecting road slopes. The study found that ALS data and its corresponding algorithm achieved better detection and delimitation results compared to MLS. Measuring the road from a terrestrial perspective negatively impacted the detection process, while an aerial perspective allowed for scanning of the entire slope structure.
Article
Engineering, Multidisciplinary
Nur Luqman Saleh, Aduwati Sali, Raja Syamsul Azmir Raja Abdullah, Sharifah M. Syed Ahmad, Jiun Terng Liew, Fazirulhisyam Hashim, Fairuz Abdullah, Nur Emileen Abdul Rashid
Summary: This study introduces an enhanced signal processing scheme for detecting mouth-click signals used by blind individuals. By utilizing additional band-pass filtering and other steps, the detection accuracy is improved. Experimental results using artificial signal data showed a 100% success rate in detecting obstacles. The emerging concepts in this research are expected to benefit radar and sonar system applications.
Article
Engineering, Multidisciplinary
Jiqiang Tang, Shengjie Qiu, Lu Zhang, Jinji Sun, Xinxiu Zhou
Summary: This paper studies the magnetic noise level of a compact high-performance magnetically shielded room (MSR) under different operational conditions and establishes a quantitative model for magnetic noise calculation. Verification experiments show the effectiveness of the proposed method.
Review
Engineering, Multidisciplinary
Krzysztof Bartnik, Marcin Koba, Mateusz Smietana
Summary: The demand for miniaturized sensors in the biomedical industry is increasing, and optical fiber sensors (OFSs) are gaining popularity due to their small size, flexibility, and biocompatibility. This study reviews various OFS designs tested in vivo and identifies future perspectives and challenges for OFS technology development from a user perspective.
Article
Engineering, Multidisciplinary
Yue Wang, Lei Zhou, Zihao Li, Jun Wang, Xuangou Wu, Xiangjun Wang, Lei Hu
Summary: This paper presents a 3-D reconstruction method for dynamic stereo vision of metal surface based on line structured light, overcoming the limitation of the measurement range of static stereo vision. The proposed method uses joint calibration and global optimization to accurately reconstruct the 3-D coordinates of the line structured light fringe, improving the reconstruction accuracy.
Article
Engineering, Multidisciplinary
Jaafar Alsalaet
Summary: Order tracking analysis is an effective tool for machinery fault diagnosis and operational modal analysis. This study presents a new formulation for the data equation of the second-generation Vold-Kalman filter, using separated cosine and sine kernels to minimize error and provide smoother envelopes. The proposed method achieves high accuracy even with small weighting factors.
Article
Engineering, Multidisciplinary
Tonglei Cao, Kechen Song, Likun Xu, Hu Feng, Yunhui Yan, Jingbo Guo
Summary: This study constructs a high-resolution dataset for surface defects in ceramic tiles and addresses the scale and quantity differences in defect distribution. An improved approach is proposed by introducing a content-aware feature recombination method and a dynamic attention mechanism. Experimental results demonstrate the superior accuracy and efficiency of the proposed method.
Article
Engineering, Multidisciplinary
Qinghong Fu, Yunxi Lou, Jianghui Deng, Xin Qiu, Xianhua Chen
Summary: Measurement and quantitative characterization of aging-induced gradient properties is crucial for accurate analysis and design of asphalt pavement. This research proposes the composite specimen method to obtain asphalt binders at different depths within the mixture and uses dynamic shear rheometer tests to measure aging-induced gradient properties and reveal internal mechanisms. G* master curves are constructed to investigate gradient aging effects in a wide range. The study finds that the composite specimen method can effectively restore the boundary conditions and that it is feasible to study gradient aging characteristics within the asphalt mixture. The study also observes variations in G* and delta values and the depth range of gradient aging effects for different aging levels.
Article
Engineering, Multidisciplinary
Min Li, Kai Wei, Tianhe Xu, Yali Shi, Dixing Wang
Summary: Due to the limitations of ground monitoring stations in China for the BDS, the accuracy of BDS Medium Earth Orbit (MEO) satellite orbits can be influenced. To overcome this, low Earth orbit (LEO) satellites can be used as additional monitoring stations. In this study, data from two LEO satellites were collected to improve the precise orbit determination of the BDS. By comparing the results with GPS and BDS-2/3 solutions, it was found that including the LEO satellites significantly improved the accuracy of GPS and BDS-2/3 orbits.
