Flexible Microneedle Array Electrode with Improved Comfort, Low Impedance, and High Performance for Electrophysiological Recording

High‐fidelity electrophysiological recording is critical for wearable brain–computer interfaces and human–machine interaction. However, balancing signal quality and wearing comfort remains a challenge: wet electrodes suffer from gel dehydration, whereas conventional dry electrodes often exhibit high impedance and mechanical instability. Here, we present a flexible microneedle array (fMNA) electrode fabricated using a scalable micro‐electro‐mechanical system process. The electrode comprises octagonal pyramidal silicon microneedles coated with Au/Cr on a flexible parylene substrate, providing high conductivity, mechanical robustness, and conformal scalp contact. Integrated with a specialized denoising algorithm, the fMNA achieved a contact impedance of 7.6 kΩ@10 Hz, 1–2 orders of magnitude lower than that of commercial wet electrodes. It also exhibited excellent durability and flexibility, with a minimum bending radius of 3 mm. Its recording performance was systematically validated through electroencephalographic visual evoked potential and cognitive engagement experiments, together with electrooculography. Compared with wet electrodes, the fMNA produced 41%–46% higher signal amplitudes, a higher signal‐to‐noise ratio, improved stability, lower impedance drift, and fewer motion artifacts. These results establish the fMNA as a versatile platform for high‐quality electrophysiological recording and long‐term wearable bioelectronic monitoring.