Advancing EEG Biosensing: Novel Scalable Production of Platinum-Silicon Microneedles

This study presents the development and analysis of a silicon microneedle electrode array fabricated using a streamlined, two-step approach for enhanced bio-signal recording applications. Numerical simulations with COMSOL Multiphysics were employed to optimize the microneedle array design, focusing on mechanical stability and minimizing skin-electrode impedance. Structural analysis identified needle lengths between 500 m and 700 m as optimal for mechanical robustness, with critical load factors indicating a high resistance to buckling under applied forces. Optimal needle spacing was determined to prevent inter-needle interference and ensure effective skin penetration. Proof-of-concept electroencephalography testing confirmed that the microneedles achieved reliable bio-signal recording, comparable to traditional wet electrodes, while offering advantages such as reduced preparation time and improved user comfort. This work establishes a simple and cleanroom-compatible, scalable method for fabricating platinum-coated silicon microneedle arrays, advancing the development of wearable, user-friendly biopotential monitoring devices.