A plastic filament of poly (methyl methacrylate) (PMMA) was fabricated by extrusion. The mode confinement was simulated using numerical software. The idea is to study how the light intensity changes inside the plastic optical fiber (POF) when a bending in multiple directions is applied. The results obtained from the simulation were compared to the experimental observations. The non-circular shape of the POF allows sensing a rotation applied as well. The angle of rotation was obtained processing two images of the end facet of the fiber (one with the fiber in a reference position and one with the rotated fiber), using an intensity-based automatic image registration. The accuracy in the rotation calculation was of 0.01°.

In this work a multiparameter plastic optical fiber (POF) sensor is presented. A three lobes POF consisting of polymethylmethacrylate (PMMA) core and a fluorinated polymer (FP) for the cladding was fabricated. The aim is to use a plastic fiber with non-circular shape to implement a bending direction and rotation sensor. The mode confinement in the plastic filament obtained with the extrusion process was simulated, and the effect of bending evaluated. The POF sensor is interrogated in transmission using an LED as light source and a charge-coupled device (CCD) to capture the light intensity distribution inside the core, and then analyze the changes when a bending or a rotation is applied.

4.3 Third chapter-Influence of the hydrophobic-hydrophilic nature of PCL-and PHEMA-based polymers and their nanocomposites on their in vitro biological development ..