Study On Key Technologies Of Mems Sensors Based On Interdigital Electrodes For Environmental Monitoring

MEMS sensor attracts attention for its simple structure, good stability, highreliability, and low cost. It was used in the environmental monitoring to detectbiochemical substances in gas or aquatic environment, and had become hot spots in thefield of environmental monitoring.In this paper, a MEMS biochemical sensor based on the interdigital electrodestructure is studied systematically, including the work principle, structural optimization,fabrication process, testing and application. The results are shown as follows:1. The work principle of the interdigital electrode sensor was introduced. Against thelow level biochemical substance was difficult to detect, MEMS biochemical sensor basedon the interdigital electrode is supplied. The resistance model and design parameter wasstudied, and the influences of parameter s on interdigital electrode sensor were analyzedby optimum design. The performance of interdigital electrode sensor was optimized.2. Compared with other MEMS processing techniques, wet etching process isselected to fabricate the interdigital electrode sensor, and the fabrication processing wasdesigned. The plating of chrome/gold electrode metal layer, wet etching of interdigitalelectrode were studied. The influences of parameters on manufacturing are analyzed, andthe parameters in each process are determined by optimization. The interdigital electrodemicrostructure was completed.3. The design and fabrication of the interdigital electrode gas sensors was completed.The selecting of electrode structure, the design of process, the preparation of gas-sensitivematerial, the drawing of sensor layout was studied. The interdigital electrode gas sensorwas completed and tested, and the practicability was proved.4. The design and fabrication of the interdigital electrodes Escherichia coli sensorwas completed. The Escherichia coli biosensor based on the interdigital electrode wasintroduced. The Escherichia coli was modified on the surface of sensor by biologicalmodification techniques, and the precipitation of silver appeared in the micro gap ofinterdigital microelectrodes by chemical reduction reaction. The Escherichia coli in theaquatic environment was detected.