Title: Polymer Optical Fiber Bragg Grating Sensors for Biomedical Applications
Supervisors:
Dr. Kristian Nielsen, Development Engineer, DTU Fotonik (main supervisor)
Professor Dr. Ole Bang, DTU Fotonik
Evaluation Board:
Senior Scientist Lars René Lindvold, DTU Center for Nuclear Technologies (Chairman)
Associate Professor Kyriacos Kalli, Cyprus University of Technology, Cyprus
Prof. David J. Webb, Aston University, UK
Master of the Ceremony
Associate Professor Jakob Janting, DTU Fotonik
Abstract
Fiber Bragg gratings inscribed in polymer optical fibers is a promising technology within the field of biomedical sensing. In this thesis, the possibilites of further advancing the technology are investigated. This involves the investigation of the sensing characteristics of polymer optical fiber Bragg gratings related to both physiological and chemical parameters. The thesis demonstrates the ability of measuring hydrostatic pressure using Bragg gratings inscribed in recently developed types of polymer optical fibers consisting of the polymers Zeonex 480R and Topas 5013 and demonstrates a tranducer-free method to further enhance the sensitivity of the gratings. Moreover, it explores the possibility of creating highly sensitive fiber optic force sensors by applying an organic solvent etching process. The results show, that the force sensitivity of the polymer optical fiber Bragg gratings can be greatly enhanced without at the same time increasing the cross-sensitivity towards temperature. Based on these results, a novel type of all-polymer biocompatible pH sensor probe based on solvent etched polymer optical fiber Bragg gratings utilizing a pH-responsive hydrogel coating as a mechanical transducer is demonstrated. The presented research can lead to new biocompatible, all-polymeric optical fiber based chemical sensors and biosensors.