Microneedle biosensors represent a cutting-edge technology with the potential to revolutionize non-invasive diagnostics, especially in the continuous monitoring of cardiac health. This research project focuses on the development and optimization of a wearable microneedle patch sensor designed for the detection of cardiac biomarkers. By integrating advanced materials science and innovative fabrication techniques, this sensor aims to provide real-time, reliable, and accurate monitoring of clinically relevant biomarkers through the minimally invasive sampling of biofluids such as interstitial fluid, sweat, and tears.

The primary objective of this project was to enhance the design and functionality of microneedle-based sensors. Key areas of focus included the optimization of microneedle fabrication, substrate synthesis, electrode printing, and the integration of molecularly imprinted polymers (MIPs) for targeted biomarker detection. The microneedles were fabricated using an electrochemical etching process, selecting titanium as the material due to its biocompatibility and robustness. Various elastomer substrates were evaluated, with Styrene-Ethylene-Butylene-Styrene (SEBS) emerging as the most suitable material for the sensor, providing the necessary flexibility and durability without compromising the integrity of the sensor during use.

Electrode fabrication involved the use of direct-ink printing technology with carbon conductive ink, which was selected for its stretchability and compatibility with the substrate. To enhance the sensitivity and specificity of the sensor, MIPs were integrated as the sensing layer. The MIP layer was applied using an electropolymerization process in the presence of the target biomarker, creating a molecularly imprinted cavity for selective binding. Initial results demonstrated the successful fabrication of microneedles with diameters as small as 20 micrometers, along with the effective integration of the sensor components. The microneedles showed high adhesion when plasma-treated, and the sensor exhibited stable resistance retention under mechanical stress, such as stretching and twisting. These findings confirm the feasibility of using this sensor for continuous cardiac biomarker monitoring.

Future work will focus on further enhancing the resolution of the printed electrodes, improving the consistency of the molecularly imprinted layers, and exploring the full integration of the sensor components. Additionally, efforts will be made to incorporate wireless communication capabilities and algorithmic data analysis to create a closed-loop system that not only monitors but also responds to changes in biomarker levels. This could potentially extend the application of this technology to include drug delivery systems and other healthcare interventions, highlighting the immense potential of wearable diagnostics.