Design and Development of Fiber Bragg Grating Tactile Sensing Devices for Novel Applications in Engineering and Biomedical Fields

Abstract

Among the five human basic senses, touch is thought to be the sense that makes the world 'real' to us. Tactile sensors are a category of artificial sensors that acquire information through physical touch. Tactile sensors sense various external stimuli, such as temperature, vibration, texture, shape, softness, and normal and shear forces. In this thesis work, the design and development of novel Fiber Bragg Grating tactile sensor-based devices are presented. Further, novel packaging methodologies for FBG sensors are described. Finally, newer engineering and biomedical applications of the proposed devices are demonstrated. A diaphragm-micro-stylus-based FBG tactile sensor has been designed and developed, which can potentially be used for reading Standard English Grade-1 Braille cells. Theoretical modeling and numerical simulation of the device design have been described. The experimental results demonstrate the feasibility and the real-time applicability of the proposed FBG Tactile sensor as a Standard English Grade -1 Braille reader. A fiber Bragg grating tactile displacement sensor has been designed and developed for surface thickness and shape measurement. Theoretical modeling and numerical simulation of the sensor packaging have been discussed. Further, the proposed device’s applications in measuring thin film layer coating thickness and surface shape identification have been demonstrated. Furthermore, a new tactile thermal sensing pad has been devised for breast cancer detection based on thermography using an array of FBG sensors. The simulation process of breast tissue and the tumor is described, and the simulated tissue's surface temperature variations have been studied by varying the heater temperature. Modeling of the tissue-mimicking phantom and tumor in COMSOL Multiphysics software is discussed. Finally, a feasibility study of the device has been carried out by comparing the experimental and simulated results, and the initial result looks promising to be adopted in real-world scenarios.