Development and Characterization of Wearable Raman Scattering System for Optical Biosensing

Recent advancements in wearable technology have led to a significant improvement in personalized health monitoring. Researchers in biosensing are developing innovative devices and techniques for analyzing biomolecules, such as lactate, glucose, uric acid, DNA, and antibodies, to diagnose and monitor diseases and biological processes. A promising area of research is Raman scattering-based optical biosensing, a non-destructive, label-free analytical technique that identifies chemical compounds through the inelastic scattering of light. This method has been widely utilized in several fields, such as biology, chemistry, and medicine. The potential of Raman spectroscopy in detecting chemical compounds and properties of biomolecules is driving the development of new biosensor platforms based on the Raman effect. Translating bulky bench-sized or handheld Raman spectroscopy instruments to Wearable systems is crucial for the usability of optical Raman biosensing. They allow for continuous monitoring of biomolecules in real-time, providing more accurate information about a person's health status and eliminating the need for frequent sample collection and analysis. These systems can improve the efficiency and cost-effectiveness of healthcare delivery and patient outcomes, especially for those with chronic conditions or those in remote or resource-limited settings. This research was conducted at the Bio/CMOS Interfaces Laboratory (BCI) at EPFL Neuchâtel, Switzerland. The aim of the thesis was to address the current limitations in the field of wearable technology by developing a wearable proof-of-concept Raman scattering-based biosensing system. The research resulted in the development of an 8.8 x 9.5 x 6.5 cm³ prototype using innovative 3D printing techniques, which allowed for a modular design that facilitated the easy placement of components and flexible mountings for optics. In addition, we also developed a laser driver and optimized the temperature control system for the laser source using the well-established Nichols-Zeigler method. This ensures the device's operation with optimal efficiency and accuracy. The completed wearable platform and its results are presented, showcasing the device's suitability for biosensing. The thesis also provides a comprehensive comparison of the benefits and drawbacks of the wearable Raman spectroscopy configuration compared to other wearable optical devices.