MICROFABRICATION TECHNOLOGY OF FLEXIBLE MEMBRANE-BASED SENSORS FOR IN-VIVO APPLICATIONS

Potentiometric ion-sensitive planar microelectrode arrays, and amperometric enzyme-containing biosensors were fabricated by photolithographic microelectronic technology on a flexible polyimide substrate. The steps of the microelectronics processing are summarized in more detail than previously described. The ion-selective electrodes were tested in blood serum, whole blood, and in the hamstring muscle of anesthetized rabbits. The test and performance characteristics of planar pH are emphasized, and K+, Na+, and Ca2+ data are included in this review. New applied results are presented from experiments where the electrodes have been implanted into an in situ porcine beating heart at the midmyocardial depth in order to monitor H+ and K+ changes during the course of coronary artery occlusion.