Modeling and Design of a Miniature Parallel-Hole Raman Sensor for Physiological Glucose Detection*

Raman spectroscopy is a promising method for non-invasive glucose sensing, capable of detecting physiological glucose levels in vivo. However, traditional Raman instruments are bulky benchtop systems, requiring long optical paths and collimated light, making them unsuitable for continuous or daily monitoring. Accessible non-invasive glucose monitoring demands more compact solutions. To address this, we propose a miniature sensor employing carbon nanotube parallel-hole collimators to directly collect diffuse scattered light, bypassing traditional path length constraints. This approach reduces signal strength, a critical challenge given the weak Raman scattering of glucose. We present an early model of the optical system, along with design considerations and limitations of a miniature parallel-hole sensor. By comparing glucose Raman bands and signal-to-noise, we aim to establish whether such a sensor can achieve the sensitivity required for detecting physiologically relevant glucose concentrations and changes. We are constructing the sensor for forthcoming testing and characterization to answer this question.