Design of a MEMS-based total phosphorus sensor with a microdigestion system

This paper presents the design of a novel microelectromechanical system (HEMS)-based total phosphorus (TP) microsensor with a microdigestion system. Cobalt metal film is introduced as the sensing material of the microelectrodes, and a micro digestion bioreactor is used as the microdigestion unit. The sensing mechanism of the cobalt electrodes to the concentration of phosphate ions is demonstrated. The structure of the microdevice is designed, and the fabrication processes are presented. A preliminary testing experiment of cobalt-based microelectrodes is achieved in this paper, and the result shows a linear relationship between the potentiometric response and the concentration of phosphate ions in the buffer solution. Combining the microdigestion system that is under fabrication, this microsensor may lead to a fully automatic measurement for total phosphorus in the water environment monitoring.