Fabrication and impedance measurement of novel metal dry bioelectrode

To obtain the bioelectrodes with better stability, a novel construction of metal dry bioelectrode was designed to meet the specific application requirements of electrode performance for bioelectric impedance technique. The laser micromachining process was then employed to fabricate the microstructure arrays on the surface of dry bioelectrodes. Based on the material removal process of laser micromachining, the forming mechanism of surface microstructure arrays on the metal dry bioelectrode was further discussed. Using the two-electrode measurement method, the impedance values of electrode-skin for three types of bioelectrodes were recorded by measuring the left forearm position. Comparing to the conventional silver/silver chloride (Ag/AgCl) ECG electrode and metal planar bioelectrode, the metal dry bioelectrode with surface microstructure arrays presented less than 50 Ω variations of contact impedance and better stability because of significant improvement of contact interface between electrode and skin, suggesting that it is an outstanding candidate for long-term clinical applications.