Simply Fabricated Inexpensive Dual-Polymer-Coated Fabry-Perot Interferometer-Based Temperature Sensors with High Sensitivity

Abstract

We designed simply fabricated, highly sensitive, and cost-effective dual-polymer-coated Fabry–Perot interferometer (DFPI)-based temperature sensors by employing thermosensitive polymers and non-thermosensitive polymers, as well as different two successive dip-coating techniques (stepwise dip coating and polymer mixture coating). Seven sensors were fabricated using different polymer combinations for performance optimization. The experiments demonstrated that the stepwise dip-coated dual thermosensitive polymer sensors exhibited the highest sensitivity (2142.5 pm °C−1 for poly(methyl methacrylate)-polycarbonate (PMMA_PC) and 785.5 pm °C−1 for poly(methyl methacrylate)- polystyrene (PMMA_PS)). Conversely, the polymer-mixture-coated sensors yielded low sensitivities (339.5 pm °C−1 for the poly(methyl methacrylate)-polycarbonate mixture (PMMA_PC mixture) and 233.5 pm °C−1 for the poly(methyl methacrylate)-polystyrene mixture (PMMA_PS mixture). Thus, the coating method, polymer selection, and thin air-bubble-free coating are crucial for high-sensitivity DFPI-based sensors. Furthermore, the DFPI-based sensors yielded stable readouts, based on three measurements. Our comprehensive results confirm the effectiveness, reproducibility, stability, fast response, feasibility, and accuracy of temperature measurements using the proposed sensors. The excellent performance and simplicity of our proposed sensors are promising for biomedical, biochemical, and physical applications.

Sequential Dual Coating with Thermosensitive Polymers for Advanced Fiber Optic Temperature Sensors

“…Figure 1 shows a schematic representation of the ferrule connector fiber-head based on double-polymer layers. DPFPI sensors employ the basic principle of Fresnel reflection, which is an optical phenomenon that occurs when two media with various refractive indices (RIs) come into contact [ 16 , 27 , 28 ]. In Figure 1 , the SMF has the RI n f = 1.456, where n p 1 is the RI of the first polymer and n p 2 is the RI of the second polymer coated on the ferrule connector tip of the SMF.…”

“…The end tip of the SMF is covered with ceramic ferrule, as shown in Figure S1 . Detailed SMF information was provided in our previous study [ 16 ]. The selected polymers should have a higher RI than that of the SMF (RI SMF = 1.456) and good adhesive properties with the fiber to make high-quality sensors.…”

“…Fiber grating sensors have a low range of temperature measurements and modest sensitivity [ 12 , 13 , 14 ]. The Fabry–Perot interferometer (FPI) [ 15 , 16 ], Mach–Zehnder interferometer [ 7 ], Michelson interferometer [ 17 ], and Sagnac interferometer [ 18 ] are the four subcategories of optical fiber interferometer temperature sensors. However, high-sensitivity temperature sensors based on FPI have been the focus of recent research.…”

“…To achieve high sensitivity, the FPI configuration should be modified while considering expense, convenience, and repeatability, which are still demanding and challenging. A dual-polymer-coated Fabry–Perot interferometer (DPFPI) sensor is a potential choice to improve the temperature sensitivity [ 16 , 27 ].…”

Review of acoustical and optical techniques to measure absolute salinity of seawater

“…The Mach-Zehnder configuration has also been used with a polymer waveguide to detect nitroaromatic components (Jiang et al, 2020). Similarly, the FP configuration too has been employed with an optical fiber coated with three different polymers to measure temperature (Salunkhe et al, 2021). However, in both the cases, the resolution and the range in R.I. are not given.…”