Polymer Optical Fiber Multimaterial: Flexible and Customizable Approach in Sensors Development

Abstract

This letter presents the development and application of a multimaterial polymer optical fiber (POF) for temperature and force sensing. The POF is fabricated from the well-known polymethyl methacrylate (PMMA) through a conventional extrusion method combined with the Polycaprolactone (PCL), a biodegradable material with low melting point, which is thermally molded into the PMMA. In this approach, the high customizability enables the development of two configurations: (i) one input, one output (configuration 1); (ii) one input, two outputs (configuration 2). An advantageous feature of the PCL is its transmittance increase as a function of the temperature, which is confirmed via spectrophotometry at different temperatures. In the experimental analysis, the configuration 1 is used in the temperature tests and demonstrates a high linearity (coefficient of determination of 0.981) and resolution below 1°C, whereas its temperature limit is around 55°C. Configuration 2 is tested in simultaneous variations of temperature and transverse force, resulting in relative force insensitivity in temperatures below 40°C, whereas an optical power attenuation as a function of the applied force is found in temperatures around 55°C. Thus, the proposed approach shows a novel, flexible and customized technique for POF multimaterial fabrication, which can be employed not only on sensors applications, but also in the development of optical components based in POFs.