Batch Fabrication and Testing of Multiparameter Integrated Sensor for Marine Environmental Measurements

Miniature and multiparameter integrated water quality sensors are essential for marine environmental protection, resource exploration, and fisheries exploitation. This work describes a miniature sensor, integrating conductivity, pH, and temperature sensing units with liquid-connected Ag/AgCl reference electrode (RE) and thin-film Pt electrode array, fabricated by micro-electromechanical system (MEMS). The excellent linearity, ideal detection range, and satisfactory detection accuracy of the sensor are witnessed after a systematic performance investigation. In addition, the effect of temperature on pH and conductivity detection is investigated and a circuit module is created to collect and analyze the sensor signal. The stability and accuracy of the sensor is improved by providing real-time temperature compensation. Besides, the sensor behavior described above, the process compatibility of the physical and chemical sensor units, consistency of batch preparation, power consumption, cost, and packaging have all been thoroughly considered in this work. Undoubtedly, the highly accurate, miniaturized, sensitive, and mass-produced miniature multiparameter sensor proposed in this article is a competitive device in a wide range of marine areas for on- line monitoring of conductivity, temperature, and pH (CTpH) in situ online monitoring.