Laser-Machined Split-Ring Resonators Embedded in a Polymer Matrix for Glaucoma Monitoring

This paper presents a biosensor based on laser-machined metallic split-ring resonators embedded in hydrophilic polymer matrices for glaucoma monitoring. The inner and outer radii of the annular resonators are optimized using a finite-element model for the anterior part of the fibrous layer of human eye. The split-ring resonators are designed to have resonant frequencies in S-band. The devices are fabricated by laser cutting of 15 μm-thick aluminum sheets. Split-ring resonators are then embedded into photo-polymerized cross-linked hydrogels, which are used to prepare hydrophilic polymer matrices. The change in the resonance characteristics of the device is obtained with respect to the change in the curvature. The sensitivity of the sensor is calculated as −24.12 MHz/mm per unit change in the radius of the curvature.