Non-invasive detection using terahertz broadband spectroscopy

• Main Author: Mohamed Afiq Bin Mohamed Aris
• Other Authors: Rusli
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Physics; Terahertz
• Online Access: https://hdl.handle.net/10356/176757
• Institution: Nanyang Technological University

Given THz signal’s nature to be high in absorption to water, there are ways to take advantage of it. In current industrial application, it is used to detect harmful chemical in food and thickness of paint coating. Due to the rise in technological miniaturisation, this serves as the catalyst to combine the use of microfluidic device and THz signal’s characteristic and test the effectiveness. In this report, the goal is to verify the credibility of the 0-degree setup and analyse the dynamic changes in the composition of the THz signal with varying concentrations of Brulin and DI Water and flow rate. This assists in gathering a baseline to simulate an industrial cleaning process by using Brulin with Mineral Oil. The data is collated and analysed using OriginPro to indicate the THz signal strength response to the change in the medium and matter. It is observed that the experimental setup produces reliable result supported by theoretical findings when the THz signal interacts with DI Water. A baseline of THz signal intensity was recorded in DI water and on empty microfluidic device, providing a benchmark on the cleanliness of the microfluidic device. Brulin was found to have recovered 51% of the original THz signal intensity after 4 runs of the same Brulin solution. This application serves as a stepping stone for future THz-TDS application with a microfluidic device such as in medical diagnosis, food poisoning chemical composition and material thickness.