Surface biopotential monitoring by needle type micro electrode array

The current study reports a novel bioelectrode design based on a series of micro needle arrays for the measurement of surface biopotential. Without the pain sensation, the goal of these micro needles is to penetrate skin and minimize the variations in skin impedance, as well as body motion. Needle electrodes with high depth definition were fabricated and tested on a de-haired rat skin surface for impedance measurements. Experiment results showed a prominent reduction in electrode impedance when compared with traditional silver/silver-chloride electrodes. A quasi-linear relationship was also observed between electrode surface area and measured skin/electrode impedance.