A Potentiometric Sensor System with Integrated Circuitry for in situ Environmental Monitoring

The need to monitor the conditions prevailing in the external environment in order to control environmental pollution is one of the prime necessities of the modern age. This paper introduces a robust, self-contained, inexpensive integrated potentiometric sensor that can be used for in situ environmental monitoring. The primary focus is to design, implement and integrate a potentiometric CMOS circuit with the sensor device to measure the potential developed across a working probe (microelectrode sensor) and the reference probe. The magnitude of the output voltage signal is dependent on the characteristics (pH) of the solution being evaluated by the system. A Printed Circuit Board has been built to integrate the microelectrode sensor device and the sensor chip with the aim of producing a fully integrated system. The microelectrode sensor device may be replaced by a NEMS based sensor device in areas that require further miniaturization like biomedical applications.