The properties of integrated micro-electrodes for CMOS-compatible medical sensors

Platinum microelectrodes for invasive medical applications have been developed for blood conductivity sensors and for the detection of biopotentials. The electrodes are fabricated in a standard CMOS-technology with only one additional production step. They have been combined with analog and digital electronic components on a single silicon substrate with a size of 1×5 mm². The electrodes´ impedance characteristics, noise performance and geometrical considerations have been analysed. Due to the close neighbourhood of sensing elements and signal conditioning, integrated microsystems using integrated electrodes show enhanced resolution and a good rejection from electromagnetic distortions