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Recently, the performance of solar cell is impacted by rising panel temperatures. For solar cells to work at their best and have the longest possible useful life, the temperature of the panels must be kept at an ideal level. Current temperature sensors have a slow response time, poor accuracy, and low resolution. Meanwhile, Al2O3 and its derivatives have demonstrated a noteworthy role in temperature sensing applications due to its greater surface area, ease of synthesis, tailored optical characteristics, high melting point, and high thermal expansion coefficient. Al2O3-based nanoparticles have been employed in fiber optic-based temperature sensors as a sensing layer, a sensitivity improvement material, and a sensing matrix material. In this chapter, we discuss the function of Al2O3-based nanomaterials in evanescent wave-based temperature sensors, sensing characteristics such as sensitivity, linearity, and repeatability. The ZAZ-based sensor (Section 3.1) shows an operating temperature range between 100.9°C and 1111.0°C, the temperature sensitivity becomes 1.8 × 10−5/°C. The fabricated sensor had a linearity of 99.79%. The synthesized Al2O3 nanoparticles (Section 3.2) were given better linearity and high sensitivity (~27) at 697 nm compared with other sensing materials such as ZnO, SnO2, TiO2. The Al2O3-MgO (50–50%) (Section 3.3) demonstrated an ultrahigh sensitivity of 0.62%/°C with a better linear regression coefficient of 95%. The present advances and problems are also discussed in detail.
Department of Electronics and Communication Engineering, Sri Venkateswara College of Engineering and Technology (Autonomous), Chittoor, India
Lakshmi Narayanan Balakrishnan
Department of Physics, Government College of Technology, Coimbatore, India
Arunkumar Chandrasekhar
School of Electronics Engineering, VIT, Vellore, India
Zachariah C. Alex*
School of Electronics Engineering, VIT, Vellore, India
*Address all correspondence to: zcalex@gmail.com
1. Introduction
Solar energy is one of the more well-known renewable energy sources, and businesses and industries use its energy harvesting techniques extensively. However, one significant disadvantage of commercial solar cells is their low efficiency at higher panel temperatures. The panel temperature, solar radiation, shading, panel inclination, alignment, dust, and maintenance have a significant impact on the energy efficiency of solar cells. A one-degree temperature rise can reduce the efficiency by ~0.045% over a temperature range of 15–60°C in a monocrystalline silicon solar cell [1]. Till now more studies on the use of Al2O3 in solar cells existed. For instance, El-Shafai et al. have prepared a novel hybrid nanomaterial (HNM) (GO@CuO.γ-Al2O3) and studied their thermal and electrical performances. Different nanofluids were prepared from mono NMs (GO, CuO, and γ-Al2O3), and hybrid NMs (GO@CuO, GO@γ-Al2O3, and GO@CuO.γ-Al2O3) with water as a base fluid, to study the thermal conductivity. Different concentrations of the nanofluids (0.0625, 0.125, and 0.2%) were investigated within a temperature range of 20–50°C. Compared to water, GO@CuO.γ-Al2O3 shown maximum enhancement in thermal conductivity (22.56%) with 0.2% concentration and 50°C which is favorable for solar collector heaters. Gunjo et al. have reported that adding 5% of Al2O3 to paraffin-based nanofluids improved the melting rate by 3.46 times and discharge rate by 3 times compared with pure paraffin-based nanofluids. This increases thermal conductivity, dynamic viscosity, and density and also lowers the heat storage compared with pure paraffin-based nanofluids which favors solar energy applications. Khalifa et al. have prepared colloidal Al2O3 nanoparticles by electrolysis method and deposited over p-type silicon wafer by drop casting method and investigated solar cell performances. Mahmoud et al. have studied the performances aluminum oxide (α- Al2O3) nanoparticle and metal aluminate spinel nanoparticle (M- Al2O4, where M is Co, Cu, Ni, Zn) as photo-anodes in quantum dot photovoltaic cells. Electrochemical impedance spectroscopy shows that Zn Al2O4 and Ni Al2O4 nanocomposites have the highest lifetimes of the photogenerated electrons (τn) of 11*10−2 and 96*10−3 ms, respectively, and the lowest diffusion rates (Keff) of 9.09 and 10.42 ms−1, respectively. Amalraj et al. have reported Al2O3 nanoparticles as coolant materials show good efficiency in solar cooling panels. The solar cooling efficiency is 12 and the fill factor is 0.55. However, due to electromagnetic, chemical, and mechanical disturbances, the traditional NTC and PTC-type thermistor, thermocouples, and resistance temperature detectors (RTDs) [2] are unable to give adequate performance for certain real-time applications. Thus, fiber optic sensors would be a superior choice for these applications as the optical signal is immune to electromagnetic field interference, can be used for long-distance communication with low loss, and is compact and simple to employ in real-time applications [3].
Currently, a variety of fiber optic temperature sensors have been reported, including Fabry-Perot, Mach-Zehnder, Fiber Bragg grating, thin film on fiber core, microfiber and coating nanoscale level sensing layer at cladding modified fiber (CMF) and a fiber’s tip [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]. Of all, the CMF-based sensors outperform existing ones in all ways, including less weight, electromagnetic interference resistance, ease of manufacture, and increased accuracy in challenging conditions [16]. In CMF, a slight change in the modified nanomaterial due to temperature resulted in light intensity variation. For instance, Huang et al. [15] have reported ZrO2/Al2O3/ZrO2 (ZAZ) coated fiber optic temperature sensor and achieved better sensitivity of 1.8 × 10−5/°C. According to Sun et al. [17], an optical fiber temperature sensor based on temperature cross sensitivity with a RI sensitive device had an improved sensitivity of 350 pm/°C. Rahman et al. [18] have demonstrated bimetallic layer fiber optic temperature sensor and showed moderate temperature sensitivity. Nevertheless, these sensors have their own limitations, such as design complexity, low resolution, poor sensitivity, non-linearity, and dynamic range. By SMO coated CMF, these issues can be resolved.
Till now, a multitude of SMOs has been used in the construction of fiber optic sensors, including ZnO [19], TiO2 [20], SnO2 [21], Al2O3 [22], MgO [23], and SiO2 [24]. A substantial increase in temperature sensor research for improved linearity and sensitivity development has been observed in the last 10 years. Because of their numerous features, nanomaterials have been used in the construction of temperature sensors, greatly advancing the field of temperature sensor research. Due to their exceptional qualities, including a high melting point, a high thermal expansion coefficient, and good physical, chemical, and optical properties, Al2O3 and its nanocomposites have revolutionized the world of sensing. The thermophysical properties (Thermal Conductivity, Viscosity, Density, Specific heat) of Al2O3 nanoparticle were shown in Table 1. In temperature sensors Al2O3-based nanomaterials have been used as a sensing layer, to provide a large surface area and compatibility for temperature detection. In this review, we aim to thoroughly outline the role of Al2O3-based nanomaterials in temperature-based sensors, their present advancements, and challenges.
Recently, modern technological fields like structural, aeronautical, and aerospace engineering, as automotive, industrial, and medical engineering all heavily rely on sensors. However, till now most of the sensors are based on electrical transduction mechanism. Besides that, sensors based on optics facilitate multitude of benefits such as flexibility, anti-electromagnetic interference, low cost, and easy fabrication compared with conventional electrical sensors. The use of polymer-based fibers in the manufacture of sensors allows the researcher to create any type of fiber geometries, which is a problem with glass fiber that has not yet been resolved. Another advantage of polymer-based fiber optic sensors is the ease with which they can be modified by imprinted polymers. Materials are also another important key parameter for polymer-based optical fiber fabrication and it can be divided into two categories: plastic and natural materials. Poly(methyl methacrylate) (PMMA), cyclo-olefin polymer (COP, ZeonexTM), polycarbonate (PC), amorphous fluoropolymer (CYTOPTM), and PDMS (polydimethylsiloxane) are the most common materials for polymer-based optical fiber fabrications (Chemosensor). The fiber can be made from a single material or a combination of polymer materials when cladding and core are made from different materials. Generally, these polymers-based optical fibers provide good optical and mechanical properties, ease of access, and use [25]. POF can be produced as a single-mode [26, 27] and multimode fiber [28, 29], with a step [30] or gradient index refractive index profile [31]. The fiber has opened up a broad number of uses depending on the type of fiber, diameter of the core/cladding, refractive index of the core/cladding, numerical aperture, and dopants utilized in the fabrication process. Figure 1 shows the record of research articles in the database Scopus.
Figure 1.
The percentage of a given polymer in the total number of articles on POF published in 2015–2022 [32].
2.1 POF temperature sensing
Basically, the fiber optic sensor consists of the light source, sensor element, and detector which can be further interfaced with the data acquisition device (Figure 2). An optical fiber (single-mode or multimode) is used to direct a light source, such as a laser (narrowband source), LED (broadband source) to the spectrometer, where optical signal variations will be the measurable quantity of interest (Temperature). The temporal or spectral domains can be used to analyze the measurement signal. A photodiode and an optical spectrum analyzer or a spectrometer can be used as the detection system [33]. Generally, POF sensors offer distributed [34] and pointwise sensing measurements. However, owing to high attenuation, the POF sensors are dedicated mainly to pointwise measurement. Temperature sensing by the POF sensor can be an interaction of temperature parameter that causes changes in the intensity (amplitude), frequency, phase, and polarization of the transmitted light [35, 36, 37].
Figure 2.
The basic setup of the fiber optic sensor.
2.2 Evanescent wave absorption in optical fiber
Typically, synthesized nanoparticles (ηAl2O3 = 1.763) were used in the CMF sensor to replace the natural cladding (ηclad = 1.402). As a result, the sensor enters a leaky mode known as ηmclad> > ηcore, which results in a reduction in propagated light intensity. The evanescent absorption in the modified cladding’s changing refractive index could be the cause of the output light’s temperature-dependent intensity variation. When the light was guided through the fiber under total internal reflection at the core/modified cladding interface, a portion of the light was transmitted into the modified cladding region, where a portion will be reentered back for propagation based on the change in the modified cladding’s refractive index and the rest will be lost. The intensity of this phenomenon, known as an evanescent field, decreases exponentially the farther it is from the surface [38]. When atmosphere temperature varies, the light intensity that travels through the fiber changes as a result of changes in modified cladding refractive index which affects sensor output. The crux of temperature sensing is mainly due to changes in refractive index because of the thermal expansion and thermo-optic effect [39, 40].
2.3 Al2O3 nanomaterials for temperature sensing
The development of nanotechnology over the past 10 years has greatly sparked interest in every area of science and technology. In order to create novel materials, nanotechnology has been primarily used to reorganize bulk materials at the nanoscale. Al2O3-based nanoparticles, among other forms of nanomaterials, have drawn a lot of interest from the scientific community because of their exceptional qualities, including a high melting point, a high thermal expansion coefficient, and good physical, chemical, and optical properties. Both amorphous and crystalline phases can be found in aluminum oxide, often known as alumina (Al2O3). The crystalline form of Al2O3 has a number of metastable structural phases, including corundum, which is a stable phase with a rhombohedral structure, as well as the following: Al2O3 (monoclinic structure), Al2O3 (orthorhombic structure), Al2O3 (cubic or hexagonal structure), Al2O3 (tetragonal structure), and Al2O3 (orthoclinic structure). Aluminum (Al3+) ions and vacancies are randomly distributed throughout tetrahedral (AlO4), polyhedral (AlO5), and octahedral (AlO6) sites in amorphous Al2O3 [41, 42]. Numerous papers describe the use of Al2O3 and its composites in applications for gas sensing, environmental analysis, and temperature sensing.
2.4 Synthesis of Al2O3 nanomaterials
The synthesis of Al2O3 is done by various approaches such as sol-gel, PVD, CVD, hydrothermal, co-precipitation, solvothermal or sonochemical methods [43, 44]. Co-precipitation is one of these methods, and because of its capacity to produce large quantities of Al2O3 nanostructure at a low cost and with no environmental impact, it has the potential for application in this process. Co-precipitation was employed to synthesize Al2O3 nanoparticles. In a nutshell, 50 ml of distilled water was mixed with 2.12 g (0.2 M) of Al (NO3)2. 9H2O precursor, and the mixture was vigorously agitated for 2 hours. Drop by drop, 10 ml of 2 M NaOH stock solution was added to the previously combined solution while being constantly stirred until the pH level reached 8.0. The reacted solution was additionally left at room temperature for 24 hours. The white precipitate that resulted was then washed three times. The resultant nanoparticles were filtered and calcinated at 600°C for 4 h.
2.5 Sensor region preparation
Figure 3 depicts the schematic diagram of the metal oxide-coated temperature sensing system. The transmitted light spectra of our proposed sensor were studied using a broadband light source (SLS201/M) and an optical spectrometer. The cladding modification method was used to achieve a fiber optic temperature sensor probe (CMM). A central portion of a PMMA optical fiber was denuded and etched with an acetone solution. The synthesized metal oxide nanoparticles were mixed with double distilled water to form a paste, which was then deposited in a dip coating technique to the etched surface to a thickness of 20 μm (Figure 4). The coated optical fiber was then allowed to dry at ambient temperature and employed as a sensing region. The sensor was kept in a temperature-sensing chamber, and a heater coupled with microcontroller was used to regulate the temperature. The holder was used to clip the two ends of the fiber, preventing interference from outside disturbances. Glue was used to firmly seal the sensor chamber [46].
Figure 3.
Schematic diagram of the fiber optic temperature sensor setup [45].
Figure 4.
Scheme of probe fabrication (a) after etching (b) after coating with metal oxides as sensing layer.
In this chapter, the sensor head was built with three layers of ZrO2/Al2O3/ZrO2 (ZAZ) dielectric materials via physical vapor deposition (PVD) onto the tip of a sapphire fiber [15]. The sensor was held within a high-temperature furnace for temperature sensing following ZAZ deposition and thermal annealing. As seen in Figure 5, a 3 dB multimode optical fiber coupler, a k-type thermocouple, a broadband light source, and a fiber optic spectrometer were all used in the measurement. Due to the thermo-optic and elastic-optic effects, the refractive index and thickness of the ZAZ films will rise as the ambient temperature rises.
Figure 5.
(a) Optical interrogation system for measurement of temperature. (b) Reflection spectra of the thin-film sensor at different temperatures. (c) the variation in OPD under different temperatures of two thermal cycles. (d) Enlargement of reflection spectra around 480 nm [15].
This will cause the interference spectra to shift and the optical path difference (OPD) of the thin film interferometer to vary. Additionally, a rise in the ambient temperature will cause the interference spectra to shift. As a result, it is possible to measure the ambient temperature. When the ambient temperature changes from 100.9 to 1111.0°C, the temperature sensitivity becomes 1.8 × 10−5/°C. The fabricated sensor had a linearity of 99.79%.
3.2 Fabrication of fiber optic-based temperature sensor with various metal oxides (ZnO, SnO2, Al2O3, and TiO2) as sensing layer
The co-precipitation approach was used in this study to synthesize metal oxide semiconductors (ZnO, SnO2, Al2O3, and TiO2), which were then subjected to several material characterization techniques [47]. According to the XRD data, the ZnO nanoparticle crystallized in a hexagonal wurtzite structure, while SnO2 nanoparticles are in a rutile tetragonal structure, Al2O3 nanoparticles are in a rhombohedral structure, and TiO2 nanoparticles are in a rutile anatase structure. The SEM analysis confirms that all of the synthesized nanopowders are in grains that are dispersed equally (Figure 6). Additionally, dip coating was used to deposit the synthesized metal oxide semiconductors over the optical fiber’s cladding-modified region, and investigated temperature sensing for broad wavelength range and specific wavelength ranges (Blue, Green, Orange, Red, and Yellow). Figure 7 depicts the change in light intensity of metal oxide nanoparticles (ZnO, SnO2, Al2O3, and TiO2) at various temperatures between 35 and 75°C with a 5°C step interval.
Figure 6.
SEM micrographs of (a) ZnO, (b) SnO2, (c) TiO2, and (d) Al2O3 nanopowders [47].
Figure 7.
Spectral response of synthesized nanopowders (a) ZnO (b) SnO2 (c) TiO2 and (d) Al2O3 for various temperature (35 to 75°C) at 697 nm [47].
The three characteristic peaks appear in the spectrum at wavelengths of 697, 774, and 952 nm respectively which are the characteristic spectrum of the optical fiber used. The characteristic spectrum shows intensity variations at various temperatures. In comparison to the other two characteristic peaks, the temperature variation led to the greatest peak intensity variation at about 697 nm. Figure 8 depicts the variation in light intensity of Al2O3 nanoparticles at various temperatures, from 35 to 75°C with a step interval of 5°C (Blue, Green, Orange, Red, and Yellow). When compared to other wavelengths, it has been shown that blue and orange wavelengths displayed a significant variation in intensity. It shows that both blue and orange wavelength ranges are possible for the manufactured fiber optic temperature sensor to operate in. It reveals that the synthesized Al2O3 nanoparticles were given better linearity and high sensitivity (~27) at 697 nm compared with other sensing materials. Further, wavelength dependent temperature sensing characteristics of Al2O3 nanopowders were studied and it shows better sensitivity (~34) in the blue wavelength region (450 nm–495 nm) (Figure 9).
Figure 8.
Spectral response of Al2O3 nanopowders for various temperature (35 to 75°C) at different wavelength ranges (a) blue, (b) green, (c) orange, (d) red, and (e) yellow [47].
Figure 9.
Temperature sensitivity of (a) synthesized nanopowders at 697 nm and (b) Al2O3 nanopowder at different wavelengths [47].
3.3 Fabrication of fiber optic-based temperature sensor with Al2O3, MgO, and composites as sensing layer
Fabrication and characterization of fiber optic temperature sensors using Al2O3-MgO nanocomposite as cladding material have been reported [45]. To synthesize Al2O3, MgO, and their various compositions, the co-precipitation technique was chosen and subjected to various material characterizations. From, XRD, Al2O3 and MgO nanoparticles are in rhombohedral structure and cubic structure and Al2O3-MgO nanocomposite conceives both rhombohedral and cubic crystal structure. The SEM morphology of Al2O3, MgO, and Al2O3-MgO (25–75%, 50–50%, 75–25%) composite nanopowders showed non-uniform agglomerated nanoparticles. The EDS analysis addresses the distribution of Al, Mg, and O elements, respectively in Al2O3-MgO nanocomposite. The unclad part of an optical fiber was coated with Al2O3, MgO, and Al2O3-MgO nanocomposites to create the temperature sensor probe. The temperature sensor response has been studied in the temperature range of 35–80°C (Figure 10) and Al2O3-MgO (50–50%) composite demonstrated an ultrahigh sensitivity of 0.62%/°C with a better linear regression coefficient of 95% (Figure 11). Further, the fabricated sensor emphasizes the feature of compact sensing structure, high-temperature sensitivity, good linearity, and wide temperature measurement range.
Figure 10.
Spectral response of the sensor at different temperature range of 35–80°C (a) bare fiber (b) Al2O3 (c) MgO (d) Al2O3-MgO (25–75%) (e) Al2O3-MgO (50–50%) and (f) Al2O3-MgO (75–25%). The arrow mentioned in the figure indicates the increase in intensity of the spectra upon increase in temperature [45].
Figure 11.
(a) Temperature sensitivity of Al2O3, MgO, Al2O3-MgO (25–75%), Al2O3-MgO and Al2O3-MgO (75–25%) nanoparticles at the wavelength of 693 nm. (b) Relationship between temperature and sensitivity of Al2O3-MgO (50–50%) [45].
The future development of fiber optic temperature sensor faces challenges and opportunities, such as: (1) The development of new high-temperature-resistant optical fiber with excellent material and mechanical properties improving the temperature range of the sensor; (2) Adding durable cladding to crystal fiber highly enhances the sensing performance and long-term stability and (3) The development of sensors with multi-parameters sensing is essential along with better stability and package protection.
In summary, Al2O3-based nanomaterials have attracted significant attention of the scientific community for the fabrication of fiber optic-based temperature sensors due to their distinct electrical, mechanical, thermal, and optical properties. This article has discussed the crucial function of Al2O3-based nanomaterials in evanescent wave-based temperature sensors, as well as their present advancements and difficulties. Al2O3-based nanoparticles serve as a better sensing layer, sensitivity enhancement material, and sensing matrix material in fiber optic-based temperature sensors.
The authors would like to express their heartfelt gratitude to the Department of Science and Technology (DST), New Delhi, India, for providing financial assistance through the FIST (Fund for Improvement of S&T Infrastructure in Higher Education Institutions) project [SR/FST/ETI-015/2011].
1.Dhanalakshmi S, Chakravartula V, Narayanamoorthi R, Kumar R, Dooly G, Duraibabu DB, et al. Thermal management of solar photovoltaic panels using a fibre Bragg grating sensor-based temperature monitoring. Case Studies in Thermal Engineering. 2022;31:101834
2.Michalski JML, Eckersdorf K, Kucharski J. Temperature Measurement. 2nd ed. Chichester: Wiley; 2001
3.Webb RC, Bonifas AP, Behnaz A, Zhang YH, Yu KJ, Cheng HY, et al. Ultrathin conformal devices for precise and continuous thermal characterization of human skin. Nature Materials. 2013;12:938-944
4.Fang CF, Lee FD, Stober B, Fuller GG, Shen AQ. Integrated microfuidic platform for instantaneous flow and localized temperature control. RSC Advances. 2015;5:85620-85629
5.Hill KO, Meltz G. Fiber Bragg grating technology fundamentals and overview. Journal of Lightwave Technology. 1997;15:1263-1276
7.Zhu T, Wu D, Liu M, Duan DW. In-line fiber optic interferometric sensors in single-mode fibers. Sensors. 2012;12:10430-10449
8.Li E, Wang X, Zhang C. Fiber-optic temperature sensor based on interference of selective higher-order modes. Applied Physics Letters. 2006;89:091119
9.Choi HY, Park KS, Park SJ, Paek UC, Lee BH, Choi ES. Miniature fiber-optic high temperature sensor based on a hybrid structured Fabry–Perot interferometer. Optics Letters. 2008;33:2455-2457
10.Li M, Liu Y, Zhao X, Gao R, Li Y, Qu S. High sensitivity fiber acoustic sensor tip working at 1550 nm fabricated by two-photon polymerization technique. Sensors and Actuators A. 2017;260:29-34
11.Liu G, Han M, Hou W. High-resolution and fast-response fiber-optic temperature sensor using silicon Fabry-Pérot cavity. Optics Express. 2015;23:7237-7247
12.Zhu Y, Wang A. Surface-mount sapphire interferometric temperature sensor. Applied Optics. 2006;45:6071-6076
13.Nguyen LV, Warren-Smith SC, Ebendorff-Heidepriem H, Monro TM. Interferometric high temperature sensor using suspended-core optical fibers. Optics Express. 2016;24:8967-8977
14.Xu F, Brambilla G. Manufacture of 3-D microfiber coil resonators. IEEE Photonics Technology Letters. 2007;19:1481-1483
15.Huang C, Lee D, Dai J, Xie W, Yang M. Fabrication of high-temperature temperature sensor based on dielectric multilayer film on sapphire fiber tip. Sensors and Actuators A. 2015;232:99-102
16.Botewad SN, Pahurkar VG, Muley GG. Fabrication and evaluation of evanescent wave absorption based polyaniline-cladding modified fiber optic urea biosensor. Optical Fiber Technology. 2018;40:8-12
17.Sun H, Hu M, Rong QZ, Du Y, Yan H, Qiao X. High sensitivity optical fiber temperature sensor based on the temperature cross-sensitivity feature of RI-sensitive device. Optics Communication. 2014;323:28-31
18.Rahman A, Panchal K, Kumar S. Optical sensor for temperature measurement using bimetallic concept. Optical Fiber Technology. 2011;17:315-320
19.Zhu L, Zeng W. Room-temperature gas sensing of ZnO-based gas sensor: A review. Sensors and Actuators A. 2017;267:242-261
20.Tong X, Shen W, Chen X, Corriou J. A fast response and recovery H2S gas sensor based on free-standing TiO2 nanotube array films prepared by one-step anodization method. Ceramics International. 2017;43:14200-14209
21.Kou X, Xie N, Chen F, Wang T, Guo L, Wang C, et al. Lu G superior acetone gas sensor based on electrospun SnO2 nanofibers by Rh doping. Sensors and Actuators B: Chemical. 2018;256:861-869
22.Guo X, Pan G, Ma X, Li X, He P, Hu Z, et al. Optical excitation-enhanced sensing properties of acetone gas sensors based on Al2O3-doped ZnO. Sensor Review. 2017;37:364-370
23.Rao CN, Nakate UT, Choudhary RJ, Kale SN. Defect-induced magneto-optic properties of MgO nanoparticles realized as optical fiber-based low-field magnetic sensor. Applied Physics Letters. 2013;103:151107
24.Bai Z, Chen R, Si P, Huang Y, Sun H, Kim D. Fluorescent pH sensor based on Ag@SiO2 core–shell nanoparticle. ACS Applied Materials & Interfaces. 2013;5:5856-5860
25.Ye F, Tian C, Ma C, Zhang ZF. Fiber optic sensors based on circular and elliptical polymer optical Fiber for measuring refractive index of liquids. Optical Fiber Technology. 2022;68:102812
26.Chen CH, Tsao TC, Tang JL, Wu WT. A multi-D-shaped optical fiber for refractive index sensing. Sensors. 2010;10:4794-4804
27.Szczerska M. Temperature sensors based on polymer fiber optic interferometer. Chem. 2022;10:228
28.Prasad SG, Lal C. Spectroscopic investigations of optical bandgap and search for reaction mechanism chemistry due to-rays irradiated PMMA polymer. Biointerface Research in Applied Chemistry. 2022;13:184
29.Zuo H, Yu S, Gu T, Hu J. Low loss, flexible single-mode polymer photonics. Optics Express. 2019;27:11152-11159
30.Gutierrez-Rivera M, Jauregui-Vazquez D, Garcia-Mina DF, Sierra-Hernandez JM, EstudilloAyala JM, Almanee M, et al. Fiber optic fabry-perot micro-displacement sensor based on low-cost polymer film. IEEE Sensors Journal. 2020;20:4719-4725. DOI: 10.1109/JSEN.2019.2944998
31.Chapalo I, Theodosiou A, Kalli K, Kotov O. Multimode Fiber interferometer based on graded-index polymer CYTOP fiber. Journal of Lightwave Technology. 2020;38:1439-1445
32.Gierej A, Geernaert T, Van Vlierberghe S, Dubruel P, Thienpont H, Berghmans F. Challenges in the fabrication of biodegradable and implantable optical fibers for biomedical applications. Materials. 2021;14:1972
33.Woyessa G, Fasano A, Stefani A, Markos C, Nielsen K, Rasmussen HK, et al. Single mode step-index polymer optical Fiber for humidity insensitive high temperature Fiber Bragg grating sensors. Optics Express. 2016;24:1253-1260
34.Min R, Hu X, Pereira L, Simone Soares M, Silva LCB, Wang G, et al. Polymer optical Fiber for monitoring human physiological and body function: A comprehensive review on mechanisms, materials, and applications. Optics and Laser Technology. 2022;147:107626
35.Jedrzejewska-Szczerska M. Response of a new low-coherence Fabry-Perot sensor to Hematocrit levels in human blood. Sensors. 2014;14:6965-6976
36.Mizuno Y, Theodosiou A, Kalli K, Liehr S, Lee H, Nakamura K. Distributed polymer optical fiber sensors: A review and outlook. Photonics Research. 2021;9:1719
37.Gomez D, Morgan SP, Hayes-Gill BR, Correia RG, Korposh S. Polymeric optical fibre sensor coated by SiO2 nanoparticles for humidity sensing in the skin microenvironment Sens. Actuators B. 2018;254:887-895
38.Zhong N, Wang Z, Chen M, Xin X, Wu R, Cen Y, et al. Three-layer-structure polymer optical fiber with a rough inter-layer surface as a highly sensitive evanescent wave sensor Sens. Actuators B. 2018;254:133-142
39.Huang YW, Tao J, Huang XG. Research Progress on F-P interference-based Fiber-optic sensors. Sensors. 2016;16(9):1424
40.Villalba A, Martín JC. Interferometric temperature sensor based on a water-filled suspended core fiber. Optical Fiber Technology. 2017;33:36-38
41.Zeng X, Wu Y, Hou C, Bai J, Yang G. A temperature sensor based on optical microfiber knot resonator. Optics Communication. 2009;282:3817-3819
42.Barakat WS, Wagih A, Elkady OA, Abu-Oqail A, Fathy A, EL-Nikhaily A. Effect of Al2O3 nanoparticles content and compaction temperature on properties of Al–Al2O3 coated Cu nanocomposites. Composites Part B: Engineering. 2019;175:107140
43.Taneja S, Punia P, Thakur P, Thakur A. Synthesis of nanomaterials by chemical route. In: Thakur A, Thakur P, Khurana SP, editors. Synthesis and Applications of Nanoparticles. Singapore: Springer. DOI: 10.1007/978-981-16-6819-7_4
44.Krishnia L, Thakur P, Thakur A. Synthesis of nanoparticles by physical route. In: Thakur A, Thakur P, Khurana SP. Synthesis and Applications of Nanoparticles. Singapore: Springer. DOI: 10.1007/978-981-16-6819-7_3
45.Narasimman S, Balakrishnan L, Alex ZC. Clad-modified fiber optic ammonia sensor based on Cu functionalized ZnO nanoflakes. Sensors and Actuators A: Physical. 2020;316:112374
46.Narasimman S, Harish Babu K, Balakrishnan L, Meher S. R, Sivacoumar R, Alex, ZC. Fabrication of fiber optic based temperature sensor. Materials Today: Proceedings. 2019;9: 164-174
47.Narasimman S, Mahararana K, Kokila SK, Balakrishnan L, Alex ZC. Al2O3-MgO nanocomposite based fiber optic temperature sensor. Materials Research Express. 2018;5:115014
Written By
Subramaniyam Narasimman, Lakshmi Narayanan Balakrishnan, Arunkumar Chandrasekhar and Zachariah C. Alex
Submitted: 06 October 2022Reviewed: 13 February 2023Published: 15 March 2023
Open access peer-reviewed chapter
