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![Vacuum infusion process setup for the production of carbon fiber reinforced composite structures [86].](profile/Rogerio-Nogueira/publication/232742451/figure/fig6/AS:213890379063316@1428006848920/Vacuum-infusion-process-setup-for-the-production-of-carbon-fiber-reinforced-composite.png)
Vacuum infusion process setup for the production of carbon fiber reinforced composite structures [86].
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The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this...
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... in this study the principle of the POF sensor relied on intensity variation in a side-polished fiber. This integration allowed a real time monitoring of the production process (shown in Figure 6), including the progression of resin cure over time and the determination of the infusion rate [86]. ...Similar publications
A novel optical fiber sensor based on cascade anti-resonant reflection waveguide (ARRW) and fiber ring-shaped structure (FRSS) is proposed and experimentally demonstrated for simultaneous measurement of refractive index (RI) and temperature. The sensor is very simply fabricated by splicing ARRW and FRSS based on Mach-Zehnder interference (MZI). The...
Citations
... Single-mode POFs, whose performances are gradually improving over time at low cost, [43] are used for high-precision sensors. [44] With respect to their silica equivalent, the POF-based sensors have the inherent advantages of lower cost, higher fracture resistance, and higher biocompatibility. ...
Photonic technologies have made enormous impacts on modern medicine, advancing disease diagnostics and treatments as well as health monitoring. A long‐standing challenge in the use of light and its widespread effects in photomedicine is the finite penetration of light in tissues. However, judiciously engineered optical fibers helped overcome this challenge and advance light delivery to deep tissues with spatial precision and desired accessibility. In recent years, the development of photonic technologies including optical biomaterials, fiber functionalization, and biomedical device innovations has greatly expanded the scope of light‐based healthcare. Here, the fundamentals and materials of fiber optics to endow themselves with biocompatibility, flexibility, and diverse functionalities required for long‐term implantation are overviewed. The design strategies of lab‐on‐fiber techniques, operation requirements to construct fiber optic sensors, and their health monitoring applications as wearable and implantable devices are presented. The use of fiber optics in major light‐based therapeutic modalities including optogenetics, photodynamic therapy, photobiomodulation, photochemical cross–linking, and photothermal therapy is illustrated to enhance their effectiveness, specificity, and feasibility. In short, a comprehensive review is provided on the fiber optic techniques and the latest photonic devices, which are envisioned to evolve photomedicine in clinical and point‐of‐care practices.
... Nowadays, in the aeronautical industry, various non-contact sensors-such as capacitive, inductive, microwave, and optical-are employed to measure TC and TT in real-time. 11,12 Among all the options available, optical sensors are the most appropriate choice for harsh environments where electromagnetic immunity is not feasible. Specifically, intensity-modulated-based optical fiber displacement sensors (OFDS) offer a straightforward and cost-effective solution. ...
This work introduces a mathematical model for designing optical fiber linear and angular displacement sensors (OFLADS) capable of simultaneously measuring the distance and angle of a finite reflective target such as a mirror. Recently, fiber optical sensors have found applications across industries like medical, military, or aerospace. The advantages of fiber optics, including low manufacturing cost, high sensitivity, and immunity to electromagnetic interference, make them suitable for extreme environments. Reflective fiber sensors, which modulate reflected light intensity to measure displacement, have a simple structure and a wide measurement range. Currently, attention is directed towards OFDS. We developed the mathematical model for the OFLADS design and performed a detailed simulation analysis, including the angular and linear displacement between the reflective target and the OFLADS tip, as well as the light intensity distribution profile. We also validated experimentally the proposed mathematical model with custom-made OFLADS designs.
... In recent years, the development of new technologies made an alternative to glass possible, thanks to plastic optical fibers (POFs), which are easier to produce and to handle and can withstand smaller radii of curvature than glass [8]. Optical fiber biochemical sensors present several advantages, such as small size, versatility, remote sensing capability, and immunity to electromagnetic interference [8,9]. ...
... In recent years, the development of new technologies made an alternative to glass possible, thanks to plastic optical fibers (POFs), which are easier to produce and to handle and can withstand smaller radii of curvature than glass [8]. Optical fiber biochemical sensors present several advantages, such as small size, versatility, remote sensing capability, and immunity to electromagnetic interference [8,9]. As a consequence, POF-based Citation: Tavoletta, I.; Arcadio, F.; Renzullo, L.P.; Oliva, G.; Del Prete, D.; Verolla, D.; Marzano, C.; Alberti, G.; Pesavento, M.; Zeni, L.; et al. ...
... Due to their polymeric structure, POFs allow diversified configurations, such as U-bent configurations [14][15][16], tapered POFs [17], parallel polished POFs [18], and twisted tapered POFs [19]. However, POF-based sensors must be used at low temperatures (under 80 °C) and are affected by water absorption into the polymer material, and monomodal waveguides are most difficult to realize [8,9]. The most widely used optical sensors are those based on the surface plasmon resonance (SPR) phenomenon [20][21][22], but many other optical transduction techniques have been proposed [23,24], such as fluorescence [25], evanescent fields [26], interferometric techniques [27], fiber Bragg gratings (FBGs) [28][29][30][31][32], long-period fiber gratings (LPFGs) [33], and intensity-based sensors [34][35][36]. ...
An optical–chemical sensor based on two modified plastic optical fibers (POFs) and a molecularly imprinted polymer (MIP) is realized and tested for the detection of 2-furaldehyde (2-FAL). The 2-FAL measurement is a scientific topic of great interest in different application fields, such as human health and life status monitoring in power transformers. The proposed sensor is realized by using two POFs as segmented waveguides (SW) coupled through a micro-trench milled between the fibers and then filled with a specific MIP for the 2-FAL detection. The experimental results show that the developed intensity-based sensor system is highly selective and sensitive to 2-FAL detection in aqueous solutions, with a limit of detection of about 0.04 mg L−1. The proposed sensing approach is simple and low-cost, and it shows performance comparable to that of plasmonic MIP-based sensors present in the literature for 2-FAL detection.
... These FSS systems assisted by deep neural networks have been previously employed for a wide range of studies such as non-contact continuous patient monitoring, deflection-direction estimation of an MMF, 2D tactile sensor, and bending recognition [4][5][6][7]. Also, there exists a popular kind of MMF, known as plastic optical fiber (POF) which is made with polymer material, e.g., poly-methyl methacrylate (PMMA), etc. POFs have inherent advantages such as flexibility, high tensile strength, and susceptibility to more complex environments [8]. In this work, we mainly detect the random, multiple macro-bending loss by employing a deep learning-based convolutional neural network (CNN) namely the AlexNet model [9]. ...
The specklegram analysis due to macro-bending of optical fibers has been widely employed for different sensing purposes. In this work, we mainly detect the random, multiple macro-bending loss by employing a deep learning-based convolutional neural network (CNN) namely the AlexNet model. Here, we detect the discrete losses corresponding to six macro-bends of different radii at six different locations of plastic optical fiber (POF). The proposed model can detect the macro-bending losses with 100% detection accuracy which signifies the efficacy of the proposed AlexNet model. In perspective, our results may pave the way for developing a deep-learning methodology for the smart detection of several, discrete macro-bending losses in POFs for several sensing applications.
... Although optical fibers are generally composed of silica, POFs present the additional advantages of ease of fabrication and operation, a low cost, high flexibility, softness, a light weight, higher fracture toughness, higher strain limits, and biocompatibility when compared to silica optical fibers [3,4]. Such properties make POFs a relevant technology for applications such as sensors [5][6][7]; local area networks [1,8]; and the fabrication of devices such as tapers [9], connectors [10], couplers [11,12], gratings [13,14], and even interferometric systems [5,15]. ...
... Although optical fibers are generally composed of silica, POFs present the additional advantages of ease of fabrication and operation, a low cost, high flexibility, softness, a light weight, higher fracture toughness, higher strain limits, and biocompatibility when compared to silica optical fibers [3,4]. Such properties make POFs a relevant technology for applications such as sensors [5][6][7]; local area networks [1,8]; and the fabrication of devices such as tapers [9], connectors [10], couplers [11,12], gratings [13,14], and even interferometric systems [5,15]. ...
We propose a spectral filter based on a plastic optical fiber with micro-holes as a low-cost, robust, and highly reproducible spectral filter. The spectral filter is explored for two configurations: a fiber extended in a straight line and a fiber optic loop mirror scheme configuration. The transmission traces indicate a spectral blue shift in peak transmission, at 587 nm, 567 nm, 556 nm, and 536 nm for zero, one, two, and three holes in the fiber, respectively. The filter exhibits a bandpass period of approximately 120 nm. Additionally, we conduct a comparison of the transmission with holes separated by distances of 1 cm and 500 μm. The results demonstrate that the distance between holes does not alter the spectral transmission of the filter. In the case of the fiber loop mirror configuration, we observe that the bandpass can be adjusted, suggesting the presence of multimode interference. Exploring variations in the refractive index within the holes by filling them with glucose solutions at various concentrations, we determine that the filtering band and spectral shape remain unaltered, ensuring the stable and robust operation of our spectral filter.
... Intensity-variation-based sensors offer a cost-effective alternative, analyzing power variations concerning a specific measurement [25]. Nevertheless, their low sensitivity and susceptibility to light source power variation necessitate additional compensation techniques to maintain accuracy and reliability [26]. ...
Optical fiber sensors have been studied, developed, and already used in the industry for more than 50 years due to their multiplexing capabilities, lightweight design, compact form factors, and electromagnetic field immunity. The scientific community continuously studies new materials, schemes, and architectures aiming to improve existing technologies. Navigating through diverse sensor technologies, including interferometry, intensity variation, nonlinear effects, and grating-based sensors, fiber specklegram sensors (FSSs) emerge as promising alternatives due to their simplicity and low cost. This review paper, emphasizing the potential of FSSs, contributes insights to the present state and future prospects for FSSs, providing a holistic view of advancements propelling FSSs to new frontiers of innovation. Subsequent sections explore recent research, technological trends, and emerging applications, contributing to a deeper understanding of the intricacies shaping the future of FFS sensor technologies.
... Among them, the most simple and cost-effective are the intensity modulated-based ones, namely the optical fiber displacement sensors (OFDS), which use the reflected light intensity to measure the displacement. 8 In this work we have designed and manufactured an OFDS with enhanced working range and sensitivity for accurate TC and TT measurements in aeronautical applications. This manuscript is organized in the following manner: first, we explain the functioning principles of an OFDS and the limitations of the current designs. ...
Optical fiber displacement sensors (OFDS) offer several advantages over conventional sensors due to their compact size and immunity to electromagnetic interference. These are particularly useful for applications in confined spaces, including aeronautical turbines. The critical component of OFDS is the fiber bundle, whose response depends on the arrangement, radius, and number of fibers. We developed a straightforward yet effective method for designing OFDSs based on sensor specifications: working point, range, and sensitivity. This allows to determine the bundle geometry directly from the specified requirements. Among the explored designs, the tetrafurcated bundle stands out, composed by a transmitting fiber at the center, surrounded by three collections of receiving fibers. This paper demonstrates that tetrafurcated OFDS designs significantly enhance both the range and linearity. Additionally, they effectively reduce the dead zone of the sensors, enabling precise measurements even at very short distances. The design has been manufactured and experimentally validated. Simulation and measurements are in good agreement with an MSE of 0.26%. Our findings highlight the practicality and reliability of tetrafurcated OFDS designs, opening new possibilities for advanced displacement sensing applications.
... Although optical fibers are generally made of silica, POF presents the additional advantages of ease of fabrication and operation, low cost, high flexibility, softness, light-weight, higher fracture toughness, higher strain limits, and biocompatibility when compared to silica optical fibers [3,4]. Such properties make the POF a relevant technology for applications such as sensors [5][6][7]; local area networks [1,8]; and fabrication of devices such as tapers [9], connectors [10], couplers [11,12], gratings [13,14], and even interferometric systems [13,15,16]. ...
We propose a spectral filter based on Plastic Optical Fiber with micro-holes as a low-cost, robust, and highly reproducible spectral filter. The spectral filter is explored for two configurations: fiber extended in a straight line, and a fiber optic loop mirror scheme configuration. The transmission traces indicate a spectral blue shift of peak transmission, at 587 nm, 567 nm, 556 nm, and 536 nm for 0, 1, 2, and 3 holes in the fiber, respectively. The filter exhibits a bandpass period of approximately 120 nm. Additionally, we conducted a comparison of the transmission with holes separated by distances of 1 cm and 500 μm. The results demonstrate that the distance between holes does not alter the spectral transmission of the filter. In the case of the fiber loop mirror configuration, we observed that the bandpass can be adjusted, suggesting the presence of multimode interference. Exploring variations in the refractive index within the holes by filling them with glucose solutions at various concentrations, we determined that the filtering band and spectral shape remains unaltered, ensuring a stable and robust operation of our spectral filter.
... Plastic optical fibers (POF) contain a respiration sensing part, a light source, and a photodiode deamplifier system. The intensity of the reflected light changes due to the respiratory movements of the chest and, thus, the distance between the mirror and the distal end of the POV changes and these changes are recorded, and the RR is obtained [123,124]. The POF breathing sensor in the form of a textile belt was presented by Krehel et al. [125]. ...
This article explores the importance of wearable and remote technologies in healthcare. The focus highlights its potential in continuous monitoring, examines the specificity of the issue, and offers a view of proactive healthcare. Our research describes a wide range of device types and scientific methodologies, starting from traditional chest belts to their modern alternatives and cutting-edge bioamplifiers that distinguish breathing from chest impedance variations. We also investigated innovative technologies such as the monitoring of thorax micromovements based on the principles of seismocardiography, ballistocardiography, remote camera recordings, deployment of integrated optical fibers, or extraction of respiration from cardiovascular variables. Our review is extended to include acoustic methods and breath and blood gas analysis, providing a comprehensive overview of different approaches to respiratory monitoring. The topic of monitoring respiration with wearable and remote electronics is currently the center of attention of researchers, which is also reflected by the growing number of publications. In our manuscript, we offer an overview of the most interesting ones.
... POF or plastic optical fiber sensors have become a viable alternative to silica fiber due to their lower cost, ease of installation and coupling, and durability [10]. Bent and side polished POFs have been proposed as discrete sensing elements or helically mounted on a solid support [11]. ...
