Design and Fabrication of Thick Film Dissolved Oxygen Sensor Based on RuO_2 Working Electrodes for Water Quality Monitoring

摘要

A Dissolved Oxygen (DO) sensor has been designed and fabricated on an 8.5 x 22.5 mm Alumina substrate using thick film technology. The structure of the sensor device consisted of AgPd working/counter electrode, Ag/AgCl reference electrode, RuOsub2/sub active layer, KCl electrolyte, and TiOsub2/sub membrane. Formation of the Ag/AgCl reference electrode was done by chlorination of Ag layer using FeClsub3/sub, and the TiOsub2/sub membrane was formed by screen printing of TiOsub2/sub paste. Measurement was done to study the sensor’s performance based from the current-voltage characteristics between 1.1 – 1.6 V. The results showed that a stable diffusion current was obtained when the input voltage was 1.4 V, resulting in the best sensor performance with a sensitivity of 0.560 μA l/mg and a stable step response time of 4 min. The device showed highly potential to be used as candidate for online water quality monitoring system.