Applications Of Fiber Optic Sensors Research Articles

Quantitative Experimental and Theoretical Research using the DFT Technique on the Structural, UV, Electronic, and FMO Properties of Gammaxene

This investigation gives the exploratory and theoretical purpose behind the distinctive evidence of nuclear structure, expanding and bowing developments, sub-nuclear geometry, powerful UV assessment using density functional theory (DFT) system with a B3LYP/6-311++ basis set. Optical maintenance territory is ideal for fiber optic sensor applications, and the disclosures tend to describe the straightforwardness of γ - HCH. Furthermore, frontier molecular orbital (FMO), UV-Visible NIR, was evaluated and seen as flawless with the exploratory characteristics. The HOMO-LUMO essentialness levels' uniqueness chooses the molecule's engine steadfastness, substance reactivity, compound non-abrasiveness, and hardness. The molecular electrostatic potential (MEP) is a critical mechanical assembly in electrophilic and nucleophilic goals affirmation. To recognize the reflection planes in the GME and to check the crystalline flawlessness of the GME, powder X-beam diffraction examples of the powdered example has been recorded utilizing a Reich Seifert diffractometer with CuKα (λ = 1.5418 Ǻ) radiation at 30 kV, 40 mA. In addition, ADMET boundaries, bioactivity radar, and scores are calculated using Swiss ADME and ADMET pointers to measure sub-atomic descriptors as well as to overview nuclear components.

A Review of Recent Distributed Optical Fiber Sensors Applications for Civil Engineering Structural Health Monitoring.

The present work is a comprehensive collection of recently published research articles on Structural Health Monitoring (SHM) campaigns performed by means of Distributed Optical Fiber Sensors (DOFS). The latter are cutting-edge strain, temperature and vibration monitoring tools with a large potential pool, namely their minimal intrusiveness, accuracy, ease of deployment and more. Its most state-of-the-art feature, though, is the ability to perform measurements with very small spatial resolutions (as small as 0.63 mm). This review article intends to introduce, inform and advise the readers on various DOFS deployment methodologies for the assessment of the residual ability of a structure to continue serving its intended purpose. By collecting in a single place these recent efforts, advancements and findings, the authors intend to contribute to the goal of collective growth towards an efficient SHM. The current work is structured in a manner that allows for the single consultation of any specific DOFS application field, i.e., laboratory experimentation, the built environment (bridges, buildings, roads, etc.), geotechnical constructions, tunnels, pipelines and wind turbines. Beforehand, a brief section was constructed around the recent progress on the study of the strain transfer mechanisms occurring in the multi-layered sensing system inherent to any DOFS deployment (different kinds of fiber claddings, coatings and bonding adhesives). Finally, a section is also dedicated to ideas and concepts for those novel DOFS applications which may very well represent the future of SHM.

Fiber Optic Sensing Technologies for Battery Management Systems and Energy Storage Applications.

Applications of fiber optic sensors to battery monitoring have been increasing due to the growing need of enhanced battery management systems with accurate state estimations. The goal of this review is to discuss the advancements enabling the practical implementation of battery internal parameter measurements including local temperature, strain, pressure, and refractive index for general operation, as well as the external measurements such as temperature gradients and vent gas sensing for thermal runaway imminent detection. A reasonable matching is discussed between fiber optic sensors of different range capabilities with battery systems of three levels of scales, namely electric vehicle and heavy-duty electric truck battery packs, and grid-scale battery systems. The advantages of fiber optic sensors over electrical sensors are discussed, while electrochemical stability issues of fiber-implanted batteries are critically assessed. This review also includes the estimated sensing system costs for typical fiber optic sensors and identifies the high interrogation cost as one of the limitations in their practical deployment into batteries. Finally, future perspectives are considered in the implementation of fiber optics into high-value battery applications such as grid-scale energy storage fault detection and prediction systems.

Evaluating Self-sensing Property of Carbon Fibre Cement Composite by experimental study and Finite Element Modelling For Structural Health Monitoring Applications

Structural health monitoring (SHM) is a novel area of research and it is the process of implementing a damage detection strategy. The initial step of implementation a SHM system involves, incorporating structural self-sensing capability of material to achieve the reliability and possesses long term stability. Smart sensing technologies involves the applications of fiber optic sensors and self-diagnosing fiber reinforced composites which possess important capabilities of monitoring various physical or chemical parameters to achieve the durable service life of structures. The addition Carbon fiber to concrete composites possess the electric properties, therefore it can be used as Smart sensing composite that provide the capability of non-destructive flaw detection in structures. In this paper, carbon fiber (CF’s) is added to cement composite to attain piezoresistive properties of composite. This carbon fiber is added in the composite by forming tube which act as conductive element. Later on, electromechanical test is conducted to this sensor by embedded into structural elements that is in beam and column to evaluate self-sensing properties. Scanning electron microscope is carried to understand the morphology of sample. A Finite elemental modeling is done to validate this experimental result. A FEA modelling is carried out using ANSYS software, subjected to steady steady static loading and electric analysis were done. Form the experimental is observed that addition carbon fiber induces conductivity property and the resistance decrease for failure load. The resistivity from experimental study observed is 9.2 kilo ohms and 11.2 kilo ohms for embedded carbon fibre sensor into beam and column respectively. The percentage error in electrical analysis of experimental tests compared with analytical modelling, found to be 15 %. Based on these results it can be concluded that carbon fiber cement composites have great potential and they can be used for structural health monitoring applications.

Complex application of fiber optic sensors and computed X-ray tomography for non-destructive testing of three-layer composite power elements of construction

Complex application of fiber optic sensors and computed X-ray tomography for non-destructive testing of three-layer composite power elements of construction

Strain, natural frequency, damping coefficient and elastic modulus of mortar beams determined by fiber Bragg grating (FBG) sensors

Abstract Structural health monitoring can detect anomalies in time, allowing the implementation of more efficient maintenance and repair actions in special engineering structures. An alternative in the monitoring and evaluation of structures in civil engineering is the use of optical fibers inscribed with Bragg gratings (FBG or Fiber Bragg Grating). This paper aims to compare available techniques to estimate the elastic module of cementitious composites, as well as contribute to the application of optical fiber sensors in the monitoring of strain, natural vibration frequency, damping coefficient and elastic modulus of mortar beams. The FBG sensors manufactured and calibrated by the authors presented a good precision for measuring those parameters in mortar samples. The results show that FBG sensors and strain gauge sensors present a similar result for strain and estimation of the elastic module (static and dynamic), therefore, bare FBGs could be further investigated for non-destructive testing.

Bend loss fiber optics design based on sinusoidal and ellipse configurations

Bending losses in optical fibers comprise one of the extrinsic attenuations that contribute to optical loss and they are essential for optical fiber bending sensor applications. This work investigated the optical loss in a standard single-mode step-index fiber optics due to fiber bending at 1550 nm wavelength. Variations in macro-bending loss with curvature radius and turn number have been measured. Curvature radius and turn number are examined for sinusoidal and elliptical shaped bending configurations. It has been found that the loss increases as the bending radius and number of turns increase. The result also showed that elliptical shaped bending configuration produced more loss in contrast to that of sinusoidal shaped at bending angles of 180° and 360°. The study on the macro-bending loss in terms of curvature radius and turn number for both elliptical and sinusoidal shaped bending configurations is beneficial for future fiber optic sensor applications.

Optical Fiber Sensors for Biocide Monitoring: Examples, Transduction Materials, and Prospects.

Antifouling biocides are toxic to the marine environment impacting negatively on the aquatic ecosystems. These biocides, namely, tributyltin (TBT) and Cu(I) compounds, are used to avoid biofouling; however, their toxicity turns TBT and Cu(I) monitoring an important health issue. Current monitoring methods are expensive and time-consuming. This review provides an overview of the actual state of the art of antifouling paints' biocides, including their impact and toxicity, as well as the reported methods for TBT and Cu(I) detection over the past decade. The principles of optical fiber sensors (OFS) applications, with focus on environmental applications, and the use of organic chemosensors in this type of sensors are debated. The multiplexing ability of OFS and their application on aquatic environments are also discussed.

On the integration of FBG sensing technology into robotic grippers

Modern industrial processes aim for the continuous production of small volumes tailored to the customer’s needs. Machines and robotic platforms have to be more and more adaptable, flexible, and able to cope with complex scenarios where sensing and manipulation capabilities are the key technology to succeed. The literature has plenty of capacitive, resistive, piezoelectric, and piezoresistive sensors used as tactile or force sensors. All of them present some drawbacks like non-linear behavior, sensitivity to temperature or electromagnetic noise, and hysteresis, among others. Other sensing systems are bulky and hard to integrate, sometimes jeopardizing the dexterity and manipulability of the gripper. In this context, the manuscript proposes fiber Bragg grating (FBG) optical fiber as a tactile sensing element to capture the interaction forces during material handling and object manipulation since it has numerous advantages compared with the other sensing devices. The work also offers a methodology to easily integrate the fiber in industrial grippers and introduces a set of tests useful to characterize the sensors. Custom gripper fingers have been realized in rapid prototyping to present a pictorial example of such an integration. Finally, the essay presents some experiments that assess the capability of a tactile sensor based on FBG optical fiber showing as it can correctly perceive the contact forces (NRMSE = 0.75%) and can recognize the material of the object that is being manipulated. The authors believe that the application of optical fiber sensor as tactile feedback can be useful in industrial scenarios to enable complex manipulation activities.

Applications of Fiber Optic Sensor for Monitoring and Early Warning of Soil Shift on IoT based System

A fiber optic sensor system has been designed to monitor ground shift using a multimode FD-620-10 step index fiber optic cable equipped with an IoT-based data transmission system. The sensor system consists of a light source in the form of a diode laser, a fiber optic cable light wave guide, and an OPT101 photodetector. Data processing is done using the Arduino Uno R3 microcontroller and data transmission to the server using the Arduino Ethernet Shield. Localhost is a webserver that displays measurement data and sends e-mail early warning notification of ground shift hazards. Optical fiber is used to measure the value of ground displacement by utilizing changes in output voltage. The change in output voltage occurs due to variations in the change in the diameter of the optical fiber arch. The results of sensor testing obtained an average measurement error of 1.53%.

Knee monitoring device based on optical sensor embedded in mechanical compartment assembly

Development of various health monitoring devices for health monitoring applications such as spine monitoring, respiration rate, heart rate, as well as upper and lower limb motion detections are at increasing rate. The use of optical fiber-based devices provides significant contribution in this area due to their advantages such as immunity to electromagnetic interference, lightweight and possibly small sensor setup. However, the application of intensity-based optical fiber sensor for human joint motion detections resulted in limited detection angle, where most sensor are not able to detect more than 90 deg. angle. To improve this limitation, we propose an optical sensor approach with mechanical-assisted components assembly that translates angular movement to linear movement. The light detection on the photodiode array at different pixels is analyzed to represent the angle movement of the knee. Based on our study, the proposed device can be applied to detect angle between 0−160° with an accuracy of 0.08°. The obtained results make it possible to apply this technique as knee monitoring device.

Trends and Applications of U-Shaped Fiber Optic Sensors: A Review

Intrinsic U-shaped fiber optic sensors (FOSs) are well established in the field. With greater penetration depth and evanescent power, these sensors exhibit profound sensitivity and have supported a wide range of applications. Several sensing mechanisms have been integrated with U-shaped FOSs for physical, chemical, bio, and refractive index (RI) sensing applications. Sensor performance optimization is based on the principles of the associated sensing mechanisms. This paper is the second part of a review on U-shaped FOSs and discusses the sensing mechanisms, applications, possible improvements, and future scope of the U-shaped FOSs. Besides, this paper aims to provide researchers with a general idea of the actual implementation of U-shaped FOSs based on the theoretical model discussed in Part I of this review.

Interrogation system for optical sensor using filter bank and artificial neural network

AbstractConsidering the increasingly wide application of optical fiber sensors, this article aims to present an alternative form of interrogation without the use of an optical spectrum analyzer or any other high‐cost devices. The sensor studied here is a long‐period grating being used to measure temperature. The interrogator is composed of optical filters and photodetectors whose responses are processed by a suitably trained artificial neural network. Results show that this technique enables effective interrogation of a range limited only by the optical bandwidth of the light source.

Lab-on-fiber: plasmonic nano-arrays for sensing.

For sensors based on the electromagnetic resonance whether the surface plasmon resonance (SPR) or localized surface plasmon resonance (LSPR), enhancing the light-matter interactions is the most critical and important way to improve their performance. Plasmonic nano-arrays are a kind of periodic metal or dielectric nanostructure formed by nanofabrication technology and can effectively enhance the light-matter interactions by tuning structural parameters to cause different optical effects due to their ultra-high degree of freedom. At the same time, a plug-and-play, remote microsensor suitable for limited environments (such as in vivo systems) may be realized due to the rise of lab-on-fiber technology and the progress of nanofabrication technology for unconventional substrates (such as an optical fiber tip). In this paper, the advantages and disadvantages of different nanofabrication technologies are briefly introduced and compared firstly, and then the applications of optical fiber sensors (OFS) based on different plasmonic nano-arrays are reviewed. Plasmonic nano-array OFS are divided into two categories: refractive index sensors based on the sensitivity of the array to the surrounding environment and surface enhanced Raman scattering (SERS) sensors based on the enhancement ability of the local electric field around the array. In this review, the present sensors are compared and analyzed from the aspects of the geometry, material and dimensions of plasmonic nano-arrays and the main research directions and progress are summarized. Finally, the future development trend is proposed.

Optical cellulose fiber made from regenerated cellulose and cellulose acetate for water sensor applications

In this study an optical cellulose fiber for water sensoring was prepared by using a sequential preparation strategy. The core of the fiber was prepared from dissolved cellulose, in [EMIM]OAc, which was dry–wet spun into water. The cladding layer on the cellulose core was produced by coating a layer of cellulose acetate, dissolved in acetone, using a filament coater. The chemical and optical properties of both regenerated cellulose and cellulose acetate were studied from cast films using ultraviolet–visible and Fourier-transform infrared spectroscopy measurements. Regenerated cellulose film was observed to absorb UV light, passing the visible light wavelengths. Cellulose acetate film was observed to pass the whole light wavelength range. The mechanical strength and topography of the prepared optical cellulose fiber were investigated through tensile testing and SEM imaging. The mechanical performance of the fiber was similar to previously reported values in the literature (tensile strength of 120 MPa). The prepared optical fiber guided light in the range of 500–1400 nm. The attenuation constant of the cellulose fiber was observed to be 6.3 dB/cm at 1300 nm. The use of prepared optical cellulose fiber in a water sensor application was demonstrated. When the fiber was placed in water, a clear attenuation in the light intensity was observed. The studied optical fiber could be used in sensor applications, in which easy modifiability and high thermal resistance are beneficial characteristics.Graphic abstractCoaxial cellulose acetate-regenerated cellulose fiber for transporting light in sensor optical fiber sensor applications.

High accuracy temperature sensing system exploiting a Sagnac interferometer and an optoelectronic oscillator

A temperature sensing system with high measurement accuracy based on a Sagnac interferometer (SI) and an optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The polarization maintaining fiber (PMF) constituting the SI, is employed as the sensing unit such that the free spectrum range (FSR) of the SI changes when the PMF experiences temperature variations, which results in the frequency shifts of the oscillating signal. The frequency response of the OEO with respect to the temperature is investigated, and the sensitivity of the proposed temperature sensing system is measured to be −2660.6 kHz/°C. The stability of the OEO is also discussed, and the high measurement accuracy of 0.0173 °C implemented by a fiber ring resonator (FRR) is obtained. Furthermore, the combination of traditional SI and OEO allows for the high-speed interrogation of the proposed system and extends the applications of traditional fiber optic sensors.

Simulation analysis of the optical properties of a liquid crystal-filled microstructured optical fiber

The optical properties of a liquid crystal-filled microstructured optical fiber (LC-MOF) were investigated using the finite element method. Liquid crystal E7 was designed to be infiltrated into six small air holes at the neighbourhood of silica core. Simulation results showed that the designed LC-MOF supported a continuous transmission in the silica core over a wide wavelength range. The optical properties of core modes such as refractive index, birefringence, confinement loss, model area, group refractive index, group birefringence, and zero dispersion wavelength, were illustrated. The structure parameters of LC-MOF and temperature could be used to adjusted the optical properties. The designed LC-MOF, providing a way for filling high refractive index materials in MOF air holes, has potential applications in optical fiber modulators and sensors.

Design, Fabrication, Characterization, and Application of an Ultra-High Temperature 6H-SiC Sapphire Fiber Optic Vibration Sensor

A 6H-SiC Sapphire fiber optic vibration sensor that can work at 1200 °C was designed, fabricated and tested in this paper. A sapphire fiber and a 6H-SiC vibration-sensitive element constituted the Fabry-Perot resonant cavity. The laser was input via the sapphire fiber, enabling the vibration signal to be converted to an optical signal through the Fabry-Perot cavity, and the vibration parameters were obtained by optical demodulation. The vibration-sensitive element consisted of a cantilever structure, whose structure parameters were determined by the combination of theoretical analysis and simulation. A nanosecond laser was employed to fabricate the 6H-SiC vibration-sensitive element to improve the processing efficiency and simplicity. The sensor was tested from room temperature to 1200 °C. The results showed that its frequency measurement sensitivity remains 0.9997 Hz/Hz from room temperature to 1200 °C, with the full-scale precision being 0.44% F.S. The sensor's output voltage is linearly correlated with the vibration acceleration from ambient temperature to 800 °C, making the acceleration measurement sensitivity 17.86 mV/g at 800 °C. The maximum frequency measurement error was 4.72 Hz when the sensor was at the field application of high temperature casting.

Investigation of Distributed Moisture and Temperature Measurements in Transformers Using Fiber Optics Sensors

The measurement of water inside a transformer is essential to maintain its reliable operation, as the water content can increase as the transformer ages. This measurement is frequently performed by a utility as a part of its periodic maintenance activities. In this paper, the application of optical fiber sensors as an online method to measure water content of paper inside an operating transformer is presented. There are several advantages of using these sensors, including their size, lightweight, flexibility, multiplexing, no-electromagnetic interference, etc. A unique benefit of fiber optic technology is that sensors can be embedded into the winding structure and operate in areas of high electric field strength. For this work, fiber optic water and temperature sensors are investigated by comparing their measurements to a commercial water activity probe immersed in oil. The study found that the determination of water content by fiber optic sensors compared closely with other techniques, which lead to the conclusion that they can be an effective technology for water measurement in an operational transformer.

Prospects of Application of FiberOptic Sensors for Studying the Combustion Processes in Two-Phase Flows with High Concentration of Disperse Phase [Review

The review is focused on the prospects for using the fiber-optic sensors (FOS) to study the combustion processes and measure the actual parameters (particle velocity and concentration, temperature and its distribution in the object, pressure, deformation, acceleration, displacement, etc.) in two-phase flows and sites of difficult access at high temperatures (800°C and higher).