Investigation of a Wireless Real-Time pH Monitoring System Based on Ruthenium Dioxide Membrane pH Sensor

This paper proposed a wireless real-time pH monitoring system. This system was associated ruthenium dioxide (RuO2) membrane pH sensor, microcontroller, liquid-crystal display (LCD), C/C++ program, and WiFi communication module to develop and use for ecosystem monitoring in the future. The ruthenium dioxide thin film of the pH sensor was deposited onto indium tin oxide (ITO) and polyethylene terephthalate (PET) substrates by the radio frequency (RF) sputtering system. The surface morphology of RuO2 thin film with scanning probe microscopy (SPM) was investigated. The electrochemical impedance analysis of RuO2 thin film was also studied.