In this study, solution processed composite films of nickel phthalocyanine(NiPc) and cobalt phthalocyanine(CoPc)are deposited by drop casting and under centrifugal force. The films are deposited on surface-type inter-...In this study, solution processed composite films of nickel phthalocyanine(NiPc) and cobalt phthalocyanine(CoPc)are deposited by drop casting and under centrifugal force. The films are deposited on surface-type inter-digitated silver electrodes on ceramic alumina substrates. The effects of illumination on the impedance and capacitance of the NiPc–CoPc composite samples are investigated. The samples deposited under centrifugal force show better conductivity than the samples deposited by drop casting technique. In terms of impedance and capacitance sensitivities the samples fabricated under centrifugal force are more sensitive than the drop casting samples. The values of impedance sensitivity(S_z)are equal to(-1.83) M?·cm^2/mW and(-5.365) M?·cm^2/mW for the samples fabricated using drop casting and under centrifugal force, respectively. Similarly, the values of capacitance sensitivity(S_c) are equal to 0.083 pF·cm^2/mW and 0.185 pF·cm^2/mW for the samples fabricated by drop casting and under centrifugal force. The films deposited using the different procedures could potentially be viable for different operational modes(i.e., conductive or capacitive) of the optical sensors. Both experimental and simulated results are discussed.展开更多
Biochemical sensors have important applications in biology,chemistry,and medicine.Nevertheless,many biochemical sensors are hampered by intricate techniques,cumbersome procedures,and the need for labeling.In the past ...Biochemical sensors have important applications in biology,chemistry,and medicine.Nevertheless,many biochemical sensors are hampered by intricate techniques,cumbersome procedures,and the need for labeling.In the past two decades,it has been discovered that liquid crystals can be used to achieve the optical amplification of biological interactions.By modifying recognition molecules,a variety of label-free biochemical sensors can be created.Consequently,biochemical sensors based on the amplification of liquid crystals have become one of the most promising sensors.This paper describes in detail the optical sensing principle of liquid crystals,sensing devices,and optical detection technologies.Meanwhile,the latest research findings are elucidated.Finally,the challenges and future research directions are discussed.展开更多
This essay explores the use of the sol-gel method based on the Congo-red reagent as an effective approach to create an optical sensor for the detection and tracking of Thorium(Ⅳ)(Th^(4+)).Upon exposure to a Th^(4+)-c...This essay explores the use of the sol-gel method based on the Congo-red reagent as an effective approach to create an optical sensor for the detection and tracking of Thorium(Ⅳ)(Th^(4+)).Upon exposure to a Th^(4+)-containing solution,the sensor exhibits significant absorption signal change that linearly correlates with Th^(4+)ion concentration across a wide range.It is capable of detecting Th^(4+)ion in the linear dynamic range of 1.7×10^(-8)to 1.1×10^(-3)mol/L,with a detection limit of 5.3×10^(-9)mol/L.This optode’s exceptional porous network,created through the sol-gel technique,contributes to its commendable performance,reliable repeatability,improved sensitivity,swift response time,and discerning selectivity.展开更多
Whether in the monitoring of critically ill patients such as shock, respiratory failure, brain injury, or in major anesthesia surgeries, it is necessary to evaluate the patient’s pO<sub>2</sub> and pH. An...Whether in the monitoring of critically ill patients such as shock, respiratory failure, brain injury, or in major anesthesia surgeries, it is necessary to evaluate the patient’s pO<sub>2</sub> and pH. An optical fiber sensor presented is capable of monitoring the presence of oxygen partial pressure (pO<sub>2</sub>) and pH in the real-time. The sensor is based on fluorescence sensing of polymer immobilized in the oxygen/pH-sensitive membranes and covalently attached to the optical fiber probe. The design of this sensor uses LED as light source, which is an excitation light source, inducing specific wavelengths of fluorescence on the oxygen/pH-sensitive membrane. The intensity and lifetime of fluorescence are related to the pO<sub>2</sub> and pH. So the pO<sub>2</sub> and pH can be measured by the relationship between the pO<sub>2</sub>/pH values and the intensity and lifetime of fluorescence. The signal conditioning system based on DSP and STM32 was used to store and process data, and display test values. The response of the sensor for pO<sub>2</sub> and pH monitoring with nitrogen (N<sub>2</sub>) as a balancing gas in the laboratory was performed. Finally, the oxygen/pH sensing scheme presented in this work is intended for using in biological, medical and environmental applications.展开更多
The safety and integrity requirements of aerospace composite structures necessitate real-time health monitoring throughout their service life.To this end,distributed optical fiber sensors utilizing back Rayleigh scatt...The safety and integrity requirements of aerospace composite structures necessitate real-time health monitoring throughout their service life.To this end,distributed optical fiber sensors utilizing back Rayleigh scattering have been extensively deployed in structural health monitoring due to their advantages,such as lightweight and ease of embedding.However,identifying the precise location of damage from the optical fiber signals remains a critical challenge.In this paper,a novel approach which namely Modified Sliding Window Principal Component Analysis(MSWPCA)was proposed to facilitate automatic damage identification and localization via distributed optical fiber sensors.The proposed method is able to extract signal characteristics interfered by measurement noise to improve the accuracy of damage detection.Specifically,we applied the MSWPCA method to monitor and analyze the debonding propagation process in honeycomb sandwich panel structures.Our findings demonstrate that the training model exhibits high precision in detecting the location and size of honeycomb debonding,thereby facilitating reliable and efficient online assessment of the structural health state.展开更多
Responsive photonic crystals(RPCs) constructed by periodic two/three-dimensional(2D/3D) photonic crystals(PCs) and responsive-material hosts,are important visualized optical sensors.Their optical diffraction color can...Responsive photonic crystals(RPCs) constructed by periodic two/three-dimensional(2D/3D) photonic crystals(PCs) and responsive-material hosts,are important visualized optical sensors.Their optical diffraction color can be tuned reversibly by external stimuli,such as pH,metal ions,biomolecules,vapors and solvents,hence leading to wide applications as visualized sensors.This review introduces the recent progress of RPCs based on 2D/3D PCs for visual detection of chemical and biological analytes,including the preparation of 2D PCs,3D PCs films,3D PCs microbeads and their applications as visualized sensors.The different cases of detecting various chemical and biological analytes by naked eyes are presented.Emphasis is given to the description of their respective sensing mechanisms with the different systems for chemical and biological analytes.Compared with 3D RPCs sensors,2D RPCs sensors have shorter response time,better stabilization and higher production efficiency,however,the diffraction intensity of 2D RPCs based on monolayered 2D polystyrene(PS) microsphere array are weak.2D RPCs sensors based on 2D Au nanosphere can significantly improve the diffraction intensity compared with traditional 2D RPCs sensors based on monolayered PS microsphere array.The much higher scattering cross section of Au nanosphere leads to 2D Au nanosphere array with ultrahigh optical diffraction intensity,which are highly helpful for their practical application as visual sensors and further quantitative detection by monitoring the diffraction peak position and intensity.展开更多
Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents ac...Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents acquisition of satellite or aerial images.This research addressed the sensitivity of the GreenSeeker handheld optical sensor to changes in orientation and height above a ryegrass canopy.Planter boxes were oriented both parallel and perpendicular to the light beam from the sensor head and heights of 30.5 cm(12”),61.0 cm(24”),91.5 cm(36”),122 cm(48”)and 152 cm(60”)were tested.Results indicated that the sensor was highly sensitive(P<0.0001)to both height above canopy and orientation of the sensor relative to the target.Operators should follow manufacturer’s recommendations on operating height range of 81-122 cm and orient the sensor head in-line with the target to obtain maximum signal response.展开更多
Herein,we report on surface plasmon(SP)-sensitive semitransparent inverted polymer photovoltaic(PV)devices that are based on multilayered material systems consisting of poly(3-hexylthiophene):fullerene-derivative bulk...Herein,we report on surface plasmon(SP)-sensitive semitransparent inverted polymer photovoltaic(PV)devices that are based on multilayered material systems consisting of poly(3-hexylthiophene):fullerene-derivative bulk-heterojunction PV layers and thin gold or silver anodes.We demonstrate that these PV devices allow the simultaneous generation of both electrical power and SPs on their anodes for photoexcitation just above the optical absorption edge of the PV layers,resulting not only in attenuated total reflection,but also in attenuated photocurrent generation(APG)under the SP resonance(SPR)condition.Moreover,we also confirm that the biomolecular interaction of biotin–streptavidin on the PV devices can be precisely detected via apparent SPR angle shifts in the APG spectra,even without the need for complex attenuated total reflection configurations.We highlight our view that APG measurements made using these PV devices show great potential for the development of future generations of compact and highly sensitive SPR-based optical sensors.展开更多
This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspir...This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspired in orb webs,which are multifunctional devices for prey capturing and vibration transmission.The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide.In this case,photocurable and polydimethylsiloxane(PDMS)resins are used for the core and cladding,respectively.The optical transmission,tensile tests,and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz,suitable for wearable applications.The BioMFOS has small dimensions(around 2 cm)and lightweight(0.8 g),making it suitable for wearable application and clothing integration.Characterization tests are performed in the structure by means of applying forces at different locations of the structure.The results show an ultra-high sensitivity and resolution,where forces in theμN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution.Then,the BioMFOS is tested on the orientation detection in 3D plane,where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit(IMU).Furthermore,the device also shows its capabilities on the movement analysis and classification in two protocols:finger position detection(with the BioMFOS positioned on the top of the hand)and trunk orientation assessment(with the sensor integrated on the clothing).In both cases,the sensor is able of classifying the movement,especially when analyzed in conjunction with preprocessing and clustering techniques.As another wearable application,the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing.Thus,the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical,biomechanics,and micro/nanotechnology.展开更多
A novel Cu(I) complex with the formula of [Cu(DPEphos)(Dicnq)]BF4(CuDD) was synthesized and characterized by X-ray single crystal diffraction method,in which DPEphos and Dicnq denote bis[2-(diphenylphosphino)phenyl]et...A novel Cu(I) complex with the formula of [Cu(DPEphos)(Dicnq)]BF4(CuDD) was synthesized and characterized by X-ray single crystal diffraction method,in which DPEphos and Dicnq denote bis[2-(diphenylphosphino)phenyl]ether and 6,7-Dicyanodipyrido[2,2-d:2',3'-f] quinoxaline,respectively.Organic ultraviolet optical sensor based on photovoltaic diode is fabricated by using CuDD as an electron acceptor and 4,4′,4″-tris-(2-methylphenyl phenylamino) triphenylamine(m-MTDATA) as an electron donor.The sensor is sensitive to UV light band from 300 to 400 nm while it has almost no response to the visible light,and under illumination of 365 nm light with power of 1.7 mW/cm2,an open circuit voltage of 1.47 V,a short circuit current of 38.9 μA/cm2,a fill factor of 0.24,and a power conversion efficiency of 0.8 % are achieved.In addition,the dependence of ultraviolet responsive sensitivity of the sensor on working temperature is also discussed.展开更多
An optical hydrogen sulfide(H_2S) sensor based on wavelength modulation spectroscopy with the second harmonic(2f) corrected by the first harmonic(1f) signal(WMS-2f/1f) is developed using a distributed feedback(DFB) la...An optical hydrogen sulfide(H_2S) sensor based on wavelength modulation spectroscopy with the second harmonic(2f) corrected by the first harmonic(1f) signal(WMS-2f/1f) is developed using a distributed feedback(DFB) laser emitting at 1.578 μm and a homemade gas cell with 1-m-long optical path length. The novel sensor is constructed by an electrical cabinet and an optical reflecting and receiving end. The DFB laser is employed for targeting a strong H_2S line at 6 336.62 cm^(-1) in the fundamental absorption band of H_2S. The sensor performance, including the minimum detection limit and the stability, can be improved by reducing the laser intensity drift and common mode noise by means of the WMS-2f/1f technique. The experimental results indicate that the linearity and response time of the sensor are 0.999 26 and 6 s(in concentration range of 15.2—45.6 mg/m^3), respectively. The maximum relative deviation for continuous detection(60 min) of 30.4 mg/m^3 H_2S is 0.48% and the minimum detection limit obtained by Allan variance is 79 μg/m^3 with optimal integration time of 32 s. The optical H_2S sensor can be applied to environmental monitoring and industrial production, and it has significance for real-time online detection in many fields.展开更多
In order to solve the problem of fouling of submerged optical instruments,an air-blast cleaning mechanism was integrated into an optical sensor used for measuring suspended sediment concentration(SSC)in natural waters...In order to solve the problem of fouling of submerged optical instruments,an air-blast cleaning mechanism was integrated into an optical sensor used for measuring suspended sediment concentration(SSC)in natural waters.Laboratory experiments in a manually created fouling environment were conducted to observe the fouling process on sensor cases made of different materials,and to verify the effectiveness of air-blast cleaning in reducing fouling.Results indicated that sensors with an aluminum case experienced more serious bio-fouling than that with polyethylene case,and the air-blast cleaning mechanism was capable of reducing fouling effect on sensor signals.So the submerged optical instruments should avoid using metal materials.The duration and frequency of air-blast cleaning can be determined and adjusted depending on actual field conditions.展开更多
A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichl...A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.展开更多
The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole p...The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole production activities in the process of oil and gas development.The authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole wellbore.These signals can clearly distinguish the vertical section,curve section,and horizontal production section.The collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 dB.By analyzing the acoustic signals in the production section,it can be located the layers with high gas production rates.Once an accurate physical model is built in the future,the gas production profile will be obtained.In addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the operation.Through the velocity analysis of the typical signals,the type of fluids in the wellbore can be distinguished.The successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.展开更多
A symmetric plasmonic structure consisting of metal-insulator-metal waveguide, groove and slot cavities is studied, which supports double Fano resonances deriving from two different mechanisms. One of the Fano resonan...A symmetric plasmonic structure consisting of metal-insulator-metal waveguide, groove and slot cavities is studied, which supports double Fano resonances deriving from two different mechanisms. One of the Fano resonances originates from the interference between the resonances of groove and slot cavities, and the other comes from the interference between slot cavities. The spectral line shapes and the peaks of the double Fano resonances can be modulated by changing the length of the slot cavities and the height of the groove. Furthermore,the wavelength of the resonance peak has a linear relationship with the length of the slot cavities. The proposed plasmonic nanosensor possesses a sensitivity of 800 nm/RIU and a figure of merit of 3150, which may have important applications in switches, sensors, and nonlinear devices.展开更多
Optical fibre sensor has the advantages of small size,light weight,anti⁃electromagnetic interference,and high measurement accuracy,which has important applications in research and industrial production.To design an op...Optical fibre sensor has the advantages of small size,light weight,anti⁃electromagnetic interference,and high measurement accuracy,which has important applications in research and industrial production.To design an optical fibre displacement sensor(OFBDS)with simple structure and high measurement accuracy,the unified model of the commonly used OFBDS structures was proposed and the feasibility of the intensity⁃modulation of multi⁃structural optical fibre bundles was analysed based on the arrangement characteristics of the fibre bundle end⁃face.The intensity⁃modulation characteristic of different fibre bundles was analysed,and the single coil coaxial fibre bundle was chosen as the fibre probe in this study.The sensor hardware system was designed.Lastly,the calibration experiment,temperature interference experiment,changes of measured plane surface area,and the dynamic experiment were conducted.Results showed that the sensor linear measurement range was about 3 mm,and the sensor system had excellent static and dynamic characteristics.展开更多
This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication i...This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication industry. In recent years, FBG sensors have found wide applications in monitoring strain, temperature, voltage and current across all industries. As the process of constructing a robust smart grid, thousands of miles of optical-fibers have been deployed along the power transmission lines for the purpose of power production communication. This paper focuses on using the power optical fiber as voltage/current sensors instead of those copper wired traditional current transformers. By using piezoelectric layers, the optical sensor is able to transform voltage/current magnitude into optical signal, as well as transmit the signal through the optical fiber. The application of using optical fiber will significantly reduce the cost of deploying traditional current transformers all around the power grid. Moreover, the optical sensor is more stable, more accurate and faster, with such characteristics, the smart grid monitoring system could be much better. The application of combining the optical composite low-voltage cable (OPLC) and the optical current sensor in the distribution network for smart distribution monitoring has been analyzed.展开更多
A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic s...A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples.展开更多
Refractometric fiber optic sensors have a number of applications in industry due to advantages like remote sensing ability, compact size, easy to fit, etc. A refractometric sensor contains a pair of parallel fibers an...Refractometric fiber optic sensors have a number of applications in industry due to advantages like remote sensing ability, compact size, easy to fit, etc. A refractometric sensor contains a pair of parallel fibers and a gap between the sensor probe and reflector, wherein the liquid whose refractive index is to be measured is filled. This paper describes the importance of mathematical modeling of this sensor. Ray tracing approach is used to model the sensor mathematically. This mathematical model is generalized for any scenario which is useful to avoid tedious trial and error techniques to design the sensor prototype. Mathematical modelling is a useful tool to optimize the gap distance for a detection of refractive index of liquid. The model is developed and analyzed rigorously considering adulteration of diesel by kerosene where refractive index varies from 1.44 to 1.46. Simulation experiments are carried out to optimize the gap distance which is found to be 6.8 mm using both models. Experiments are carried out where sensor probe is fabricated and results are analyzed. It is observed that for suggested gap distance sensor output varies almost linear over the entire range.展开更多
Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and disco...Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and discontinuities are created or propagate in the rock mass.Therefore,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability change.The authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal technology.In a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass behavior.Therefore,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground Research Center.The measurement results show that AEs occur frequently up to 1.5 m from the wall during excavation.In addition,hydraulic conductivity increased by 2e4 orders of magnitude.Elastoplastic analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused micro-fractures.Based on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.展开更多
基金supported by the Center for Advanced Materials(CAM),Qatar University,Qatar
文摘In this study, solution processed composite films of nickel phthalocyanine(NiPc) and cobalt phthalocyanine(CoPc)are deposited by drop casting and under centrifugal force. The films are deposited on surface-type inter-digitated silver electrodes on ceramic alumina substrates. The effects of illumination on the impedance and capacitance of the NiPc–CoPc composite samples are investigated. The samples deposited under centrifugal force show better conductivity than the samples deposited by drop casting technique. In terms of impedance and capacitance sensitivities the samples fabricated under centrifugal force are more sensitive than the drop casting samples. The values of impedance sensitivity(S_z)are equal to(-1.83) M?·cm^2/mW and(-5.365) M?·cm^2/mW for the samples fabricated using drop casting and under centrifugal force, respectively. Similarly, the values of capacitance sensitivity(S_c) are equal to 0.083 pF·cm^2/mW and 0.185 pF·cm^2/mW for the samples fabricated by drop casting and under centrifugal force. The films deposited using the different procedures could potentially be viable for different operational modes(i.e., conductive or capacitive) of the optical sensors. Both experimental and simulated results are discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos.62105125,62075088,and 12174155)Natural Science Foundation of Guangdong Province (Grant No.2022A1515140055)+6 种基金Research Fund of Guangdong-Hong Kong-Maco Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology (Grant No.2020B1212030010)Guangdong Provincial Key Laboratory of Semiconductor Micro Display (Grant No.2020B121202003)National Key Research and Development Program of China (Grant No.2021YFB2800801)Natural Science Foundation of Guangdong Province for Distinguished Young Scholar (Grant No.2020B1515020024)Key-Area Research and Development Program of Guangdong Province (Grant No.2019B010138004)Guangdong Basic and Applied Basic Research Foundation (Grant No.2021A1515110667)Special Project in Key Fields of the Higher Education Institutions of Guangdong Province (Grant No.2020ZDZX3022).
文摘Biochemical sensors have important applications in biology,chemistry,and medicine.Nevertheless,many biochemical sensors are hampered by intricate techniques,cumbersome procedures,and the need for labeling.In the past two decades,it has been discovered that liquid crystals can be used to achieve the optical amplification of biological interactions.By modifying recognition molecules,a variety of label-free biochemical sensors can be created.Consequently,biochemical sensors based on the amplification of liquid crystals have become one of the most promising sensors.This paper describes in detail the optical sensing principle of liquid crystals,sensing devices,and optical detection technologies.Meanwhile,the latest research findings are elucidated.Finally,the challenges and future research directions are discussed.
文摘This essay explores the use of the sol-gel method based on the Congo-red reagent as an effective approach to create an optical sensor for the detection and tracking of Thorium(Ⅳ)(Th^(4+)).Upon exposure to a Th^(4+)-containing solution,the sensor exhibits significant absorption signal change that linearly correlates with Th^(4+)ion concentration across a wide range.It is capable of detecting Th^(4+)ion in the linear dynamic range of 1.7×10^(-8)to 1.1×10^(-3)mol/L,with a detection limit of 5.3×10^(-9)mol/L.This optode’s exceptional porous network,created through the sol-gel technique,contributes to its commendable performance,reliable repeatability,improved sensitivity,swift response time,and discerning selectivity.
文摘Whether in the monitoring of critically ill patients such as shock, respiratory failure, brain injury, or in major anesthesia surgeries, it is necessary to evaluate the patient’s pO<sub>2</sub> and pH. An optical fiber sensor presented is capable of monitoring the presence of oxygen partial pressure (pO<sub>2</sub>) and pH in the real-time. The sensor is based on fluorescence sensing of polymer immobilized in the oxygen/pH-sensitive membranes and covalently attached to the optical fiber probe. The design of this sensor uses LED as light source, which is an excitation light source, inducing specific wavelengths of fluorescence on the oxygen/pH-sensitive membrane. The intensity and lifetime of fluorescence are related to the pO<sub>2</sub> and pH. So the pO<sub>2</sub> and pH can be measured by the relationship between the pO<sub>2</sub>/pH values and the intensity and lifetime of fluorescence. The signal conditioning system based on DSP and STM32 was used to store and process data, and display test values. The response of the sensor for pO<sub>2</sub> and pH monitoring with nitrogen (N<sub>2</sub>) as a balancing gas in the laboratory was performed. Finally, the oxygen/pH sensing scheme presented in this work is intended for using in biological, medical and environmental applications.
基金supported by the National Key Research and Development Program of China(No.2018YFA0702800)the National Natural Science Foundation of China(No.12072056)supported by National Defense Fundamental Scientific Research Project(XXXX2018204BXXX).
文摘The safety and integrity requirements of aerospace composite structures necessitate real-time health monitoring throughout their service life.To this end,distributed optical fiber sensors utilizing back Rayleigh scattering have been extensively deployed in structural health monitoring due to their advantages,such as lightweight and ease of embedding.However,identifying the precise location of damage from the optical fiber signals remains a critical challenge.In this paper,a novel approach which namely Modified Sliding Window Principal Component Analysis(MSWPCA)was proposed to facilitate automatic damage identification and localization via distributed optical fiber sensors.The proposed method is able to extract signal characteristics interfered by measurement noise to improve the accuracy of damage detection.Specifically,we applied the MSWPCA method to monitor and analyze the debonding propagation process in honeycomb sandwich panel structures.Our findings demonstrate that the training model exhibits high precision in detecting the location and size of honeycomb debonding,thereby facilitating reliable and efficient online assessment of the structural health state.
基金supported by the National Natural Science Foundation of China(51371165,51571189)the Anhui Provincial Natural Science Foundation(1508085JGD07)+1 种基金the Crossdisciplinary Collaborative Teams Program in CASthe CAS/ SAFEA International Partnership Program for Creative Research Teams
文摘Responsive photonic crystals(RPCs) constructed by periodic two/three-dimensional(2D/3D) photonic crystals(PCs) and responsive-material hosts,are important visualized optical sensors.Their optical diffraction color can be tuned reversibly by external stimuli,such as pH,metal ions,biomolecules,vapors and solvents,hence leading to wide applications as visualized sensors.This review introduces the recent progress of RPCs based on 2D/3D PCs for visual detection of chemical and biological analytes,including the preparation of 2D PCs,3D PCs films,3D PCs microbeads and their applications as visualized sensors.The different cases of detecting various chemical and biological analytes by naked eyes are presented.Emphasis is given to the description of their respective sensing mechanisms with the different systems for chemical and biological analytes.Compared with 3D RPCs sensors,2D RPCs sensors have shorter response time,better stabilization and higher production efficiency,however,the diffraction intensity of 2D RPCs based on monolayered 2D polystyrene(PS) microsphere array are weak.2D RPCs sensors based on 2D Au nanosphere can significantly improve the diffraction intensity compared with traditional 2D RPCs sensors based on monolayered PS microsphere array.The much higher scattering cross section of Au nanosphere leads to 2D Au nanosphere array with ultrahigh optical diffraction intensity,which are highly helpful for their practical application as visual sensors and further quantitative detection by monitoring the diffraction peak position and intensity.
文摘Handheld optical sensors recently have been introduced to the agricultural market.These handheld sensors are able to provide operators with Normalized Difference Vegetative Index(NDVI)data when cloud cover prevents acquisition of satellite or aerial images.This research addressed the sensitivity of the GreenSeeker handheld optical sensor to changes in orientation and height above a ryegrass canopy.Planter boxes were oriented both parallel and perpendicular to the light beam from the sensor head and heights of 30.5 cm(12”),61.0 cm(24”),91.5 cm(36”),122 cm(48”)and 152 cm(60”)were tested.Results indicated that the sensor was highly sensitive(P<0.0001)to both height above canopy and orientation of the sensor relative to the target.Operators should follow manufacturer’s recommendations on operating height range of 81-122 cm and orient the sensor head in-line with the target to obtain maximum signal response.
基金The authors thank H Takezoe for his careful reading and helpful comments on this paper.This work was supported by the Basic Science Research Program through National Research Foundations of Korea(NRF)Grant funded by the Korea Government(MSIP)(NRF-2010-0027963,2012R1A2A2A01015654 and 2014R1A2A1A10054643)by Kwangwoon University(2014)The authors also thank GC Kwon,JH Shin and J Choi for their helpful comments.
文摘Herein,we report on surface plasmon(SP)-sensitive semitransparent inverted polymer photovoltaic(PV)devices that are based on multilayered material systems consisting of poly(3-hexylthiophene):fullerene-derivative bulk-heterojunction PV layers and thin gold or silver anodes.We demonstrate that these PV devices allow the simultaneous generation of both electrical power and SPs on their anodes for photoexcitation just above the optical absorption edge of the PV layers,resulting not only in attenuated total reflection,but also in attenuated photocurrent generation(APG)under the SP resonance(SPR)condition.Moreover,we also confirm that the biomolecular interaction of biotin–streptavidin on the PV devices can be precisely detected via apparent SPR angle shifts in the APG spectra,even without the need for complex attenuated total reflection configurations.We highlight our view that APG measurements made using these PV devices show great potential for the development of future generations of compact and highly sensitive SPR-based optical sensors.
基金FAPES(320/2020 and 84336650)CNPq(304049/2019-0 and 427054/2018-4)+2 种基金Fundação para a Ciência e a Tecnologia(FCT)through the DigiAqua project-PTDC/EEIEEE/0415/2021.C.FCT through the CEECIND/00034/2018(iFish project)developed within the scope of the project i3N,UIDB/50025/2020&UIDP/50025/2020financed by national funds through the FCT/MEC.
文摘This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspired in orb webs,which are multifunctional devices for prey capturing and vibration transmission.The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide.In this case,photocurable and polydimethylsiloxane(PDMS)resins are used for the core and cladding,respectively.The optical transmission,tensile tests,and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz,suitable for wearable applications.The BioMFOS has small dimensions(around 2 cm)and lightweight(0.8 g),making it suitable for wearable application and clothing integration.Characterization tests are performed in the structure by means of applying forces at different locations of the structure.The results show an ultra-high sensitivity and resolution,where forces in theμN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution.Then,the BioMFOS is tested on the orientation detection in 3D plane,where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit(IMU).Furthermore,the device also shows its capabilities on the movement analysis and classification in two protocols:finger position detection(with the BioMFOS positioned on the top of the hand)and trunk orientation assessment(with the sensor integrated on the clothing).In both cases,the sensor is able of classifying the movement,especially when analyzed in conjunction with preprocessing and clustering techniques.As another wearable application,the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing.Thus,the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical,biomechanics,and micro/nanotechnology.
基金supported by the Natural Science Foundationof Jilin Province (No.20060516)the Doctoral Foundation of JilinNormal University (No.2006006 and No.2007009)the Subject and Base Construction Foundation of Jilin Normal University (No.2006041)
文摘A novel Cu(I) complex with the formula of [Cu(DPEphos)(Dicnq)]BF4(CuDD) was synthesized and characterized by X-ray single crystal diffraction method,in which DPEphos and Dicnq denote bis[2-(diphenylphosphino)phenyl]ether and 6,7-Dicyanodipyrido[2,2-d:2',3'-f] quinoxaline,respectively.Organic ultraviolet optical sensor based on photovoltaic diode is fabricated by using CuDD as an electron acceptor and 4,4′,4″-tris-(2-methylphenyl phenylamino) triphenylamine(m-MTDATA) as an electron donor.The sensor is sensitive to UV light band from 300 to 400 nm while it has almost no response to the visible light,and under illumination of 365 nm light with power of 1.7 mW/cm2,an open circuit voltage of 1.47 V,a short circuit current of 38.9 μA/cm2,a fill factor of 0.24,and a power conversion efficiency of 0.8 % are achieved.In addition,the dependence of ultraviolet responsive sensitivity of the sensor on working temperature is also discussed.
基金supported by the National Natural Science Foundation of China(Nos.60808020 and 61078041)the Natural Science Foundation of Tianjin(Nos.16JCQNJC02100,15JCYBJC51700 and 16JCYBJC15400)the National Science and Technology Support(No.2014BAH03F01)
文摘An optical hydrogen sulfide(H_2S) sensor based on wavelength modulation spectroscopy with the second harmonic(2f) corrected by the first harmonic(1f) signal(WMS-2f/1f) is developed using a distributed feedback(DFB) laser emitting at 1.578 μm and a homemade gas cell with 1-m-long optical path length. The novel sensor is constructed by an electrical cabinet and an optical reflecting and receiving end. The DFB laser is employed for targeting a strong H_2S line at 6 336.62 cm^(-1) in the fundamental absorption band of H_2S. The sensor performance, including the minimum detection limit and the stability, can be improved by reducing the laser intensity drift and common mode noise by means of the WMS-2f/1f technique. The experimental results indicate that the linearity and response time of the sensor are 0.999 26 and 6 s(in concentration range of 15.2—45.6 mg/m^3), respectively. The maximum relative deviation for continuous detection(60 min) of 30.4 mg/m^3 H_2S is 0.48% and the minimum detection limit obtained by Allan variance is 79 μg/m^3 with optimal integration time of 32 s. The optical H_2S sensor can be applied to environmental monitoring and industrial production, and it has significance for real-time online detection in many fields.
基金The authors acknowledge that this research was supported by the Environmental Security Technology Certification(ESTCP)program,U.S.Department of Defensethe National Natural Science Foundation of China(Grant No.51309103)。
文摘In order to solve the problem of fouling of submerged optical instruments,an air-blast cleaning mechanism was integrated into an optical sensor used for measuring suspended sediment concentration(SSC)in natural waters.Laboratory experiments in a manually created fouling environment were conducted to observe the fouling process on sensor cases made of different materials,and to verify the effectiveness of air-blast cleaning in reducing fouling.Results indicated that sensors with an aluminum case experienced more serious bio-fouling than that with polyethylene case,and the air-blast cleaning mechanism was capable of reducing fouling effect on sensor signals.So the submerged optical instruments should avoid using metal materials.The duration and frequency of air-blast cleaning can be determined and adjusted depending on actual field conditions.
基金Funded by the National Natural Science Foundation of China(No.61205062)the Scientific Research Foundation for Doctor of University(No.2019Y02)。
文摘A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.
基金jointly supported by the Science and Technology Program of Guangzhou (202103040003)the offshore NGHs production test projects under the Marine Geological Survey Program initiated by the China Geological Survey (DD20190226, DD20190218 and DD20221706)+2 种基金the Key Program of Marine Economy Development Special Foundation of Department of Natural Resources of Guangdong Province (GDNRC [2020] 045)the financial support from China Geological Survey (DD20221703)the National Natural Science Foundation of China (NSFC) (6210030553)。
文摘The distributed acoustic sensor(DAS)uses a single optical cable as the sensing unit,which can capture the acoustic and vibration signals along the optical cable in real-time.So it is suitable for monitoring downhole production activities in the process of oil and gas development.The authors applied the DAS system in a gas production well in the South China Sea for in situ monitoring of the whole wellbore for the first time and obtained the distributed acoustic signals along the whole wellbore.These signals can clearly distinguish the vertical section,curve section,and horizontal production section.The collected acoustic signal with the frequency of approximately 50 Hz caused by the electric submersible pump exhibit a signal-to-noise ratio higher than 27 dB.By analyzing the acoustic signals in the production section,it can be located the layers with high gas production rates.Once an accurate physical model is built in the future,the gas production profile will be obtained.In addition,the DAS system can track the trajectory of downhole tools in the wellbore to guide the operation.Through the velocity analysis of the typical signals,the type of fluids in the wellbore can be distinguished.The successful application of the system provides a promising whole wellbore acoustic monitoring tool for the production of marine gas hydrate,with a good application prospect.
基金Supported by the Ministry of Science and Technology of China under Grant No 2016YFA0301300the National Natural Science Foundation of China under Grant Nos 11374041 and 11574035the State Key Laboratory of Information Photonics and Optical Communications
文摘A symmetric plasmonic structure consisting of metal-insulator-metal waveguide, groove and slot cavities is studied, which supports double Fano resonances deriving from two different mechanisms. One of the Fano resonances originates from the interference between the resonances of groove and slot cavities, and the other comes from the interference between slot cavities. The spectral line shapes and the peaks of the double Fano resonances can be modulated by changing the length of the slot cavities and the height of the groove. Furthermore,the wavelength of the resonance peak has a linear relationship with the length of the slot cavities. The proposed plasmonic nanosensor possesses a sensitivity of 800 nm/RIU and a figure of merit of 3150, which may have important applications in switches, sensors, and nonlinear devices.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51775260)the Qinglan Project of Jiangsu Province(2017)of China and the Funds of Nanjing Institute of Technology(Grant No.CKJA201801).
文摘Optical fibre sensor has the advantages of small size,light weight,anti⁃electromagnetic interference,and high measurement accuracy,which has important applications in research and industrial production.To design an optical fibre displacement sensor(OFBDS)with simple structure and high measurement accuracy,the unified model of the commonly used OFBDS structures was proposed and the feasibility of the intensity⁃modulation of multi⁃structural optical fibre bundles was analysed based on the arrangement characteristics of the fibre bundle end⁃face.The intensity⁃modulation characteristic of different fibre bundles was analysed,and the single coil coaxial fibre bundle was chosen as the fibre probe in this study.The sensor hardware system was designed.Lastly,the calibration experiment,temperature interference experiment,changes of measured plane surface area,and the dynamic experiment were conducted.Results showed that the sensor linear measurement range was about 3 mm,and the sensor system had excellent static and dynamic characteristics.
文摘This paper concludes the case study work on the optical sensor, which is a new method for voltage and current measurement. Fiber Bragg gratings (FBG) have been developed and used for decades in the telecommunication industry. In recent years, FBG sensors have found wide applications in monitoring strain, temperature, voltage and current across all industries. As the process of constructing a robust smart grid, thousands of miles of optical-fibers have been deployed along the power transmission lines for the purpose of power production communication. This paper focuses on using the power optical fiber as voltage/current sensors instead of those copper wired traditional current transformers. By using piezoelectric layers, the optical sensor is able to transform voltage/current magnitude into optical signal, as well as transmit the signal through the optical fiber. The application of using optical fiber will significantly reduce the cost of deploying traditional current transformers all around the power grid. Moreover, the optical sensor is more stable, more accurate and faster, with such characteristics, the smart grid monitoring system could be much better. The application of combining the optical composite low-voltage cable (OPLC) and the optical current sensor in the distribution network for smart distribution monitoring has been analyzed.
基金Funded by the Natural Science Foundation of Hubei Province(No.2022CFB861)the Wenhua College Research and Innovation Team(No.2022T01)。
文摘A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples.
文摘Refractometric fiber optic sensors have a number of applications in industry due to advantages like remote sensing ability, compact size, easy to fit, etc. A refractometric sensor contains a pair of parallel fibers and a gap between the sensor probe and reflector, wherein the liquid whose refractive index is to be measured is filled. This paper describes the importance of mathematical modeling of this sensor. Ray tracing approach is used to model the sensor mathematically. This mathematical model is generalized for any scenario which is useful to avoid tedious trial and error techniques to design the sensor prototype. Mathematical modelling is a useful tool to optimize the gap distance for a detection of refractive index of liquid. The model is developed and analyzed rigorously considering adulteration of diesel by kerosene where refractive index varies from 1.44 to 1.46. Simulation experiments are carried out to optimize the gap distance which is found to be 6.8 mm using both models. Experiments are carried out where sensor probe is fabricated and results are analyzed. It is observed that for suggested gap distance sensor output varies almost linear over the entire range.
文摘Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and discontinuities are created or propagate in the rock mass.Therefore,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability change.The authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal technology.In a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass behavior.Therefore,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground Research Center.The measurement results show that AEs occur frequently up to 1.5 m from the wall during excavation.In addition,hydraulic conductivity increased by 2e4 orders of magnitude.Elastoplastic analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused micro-fractures.Based on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.
