A MONOLITHIC SENSOR ARRAY OF INDIVIDUALLY ADDRESSABLE MICROELECTRODES

A monolithic single-chip sensor array for measuring chemical and biochemical parameters has been developed and fabricated in a modified standard CMOS process. The array can be used for amperometric or potentiometric measurements in order to get a concentration-dependent spatial profile of the detected analyte. In addition to 400 working electrodes and two reference electrodes, the chip contains integrated read-out amplifiers, digital circuits for addressing the individual components and test circuits. The on-chip signal processing allows detection of chemical or biochemical analytes without any interference by the external measurement equipment. High electrode impedances and low power consumption have been achieved by using CMOS technology. Chemical modification of the electrodes is possible by applying an external voltage to the electrodes. In advantage to non-integrated solutions, the system can be used in a wide field of applications, especially for measurements in narrow passages because of the total chip size of only 14 x 14 mm.