Based On Printed Polymer Thin-film Ammonia Sensor

We studied a novel process to fabricate gas sensor by printing technology, wherein compared with tradition technology, the process need lower temperature and is more compatible to COMS technology. Additionally, the cost of the process is low. Otherwise, we also studied how to integrate the gas sensor and the wireless system. The main content and achievement in research are as follows:6. The fabrication of Polyaniline and Polypyrrole ink and the design of interdigited electrode are studied.7. The DC/AC impedance is studied and we found that when the AC frequency is between 150Hz to 2kHz, the AC impedance relate to ammonia has more sensitivity than the DC impedance relate to ammonia.8. The percent of acid in Polyaniline and Polypyrrole ink affects the sensitivity of ammonia sensor. We found that when the percent of acid in Polyaniline and Polypyrrole ink increases from 0.1% to 1.5%, the Variation of the AC impedance decreased.9. The selective of Polyaniline and Polypyrrole is also studied and we found that the water vapor and air has not sensitivity. The result shows that gas sensor based on Polyaniline and Polypyrrole is prospective in certain circumstance.10. In order to explain the change process of the AC impedance, we design and establish a fit model for the AC impedance of Polyaniline and Polypyrrole.