Development of PC application for colourimetric battery detection using Prussian blue in smart contact lenses

Abstract

This dissertation presents the development of a PC-based Graphical User Interface (GUI) application for analysing colourimetric changes in Prussian Blue (PB)-modified electrodes integrated into smart contact lenses for battery level estimation. The project explores the synthesis of PB nanoparticles, electrode fabrication through both slurry coating and electroplating, and electrochemical evaluation via half-cell and full-cell testing. Electroplated PB films demonstrated improved colour visibility but exhibited lower durability due to thinner deposition layers. A third-degree polynomial regression model was implemented to correlate the saturation (S) values extracted from PB regions in HSV colour space with the battery state of charge (SOC), enabling accurate estimation of remaining battery capacity. The GUI application efficiently processes image data, extracts key colour features, and predicts SOC with results displayed in real time. While this work focuses on battery monitoring, the underlying methodology can be extended to biosensing applications, such as glucose detection, where PB’s colour change also serves as an effective indicator. The integration of electrochromic materials and computer vision lays a strong foundation for future smart contact lens technologies capable of visual, power-free sensing.