以表面聲波元件為基礎之可撓二氧化碳感測器

The Design of Mobile & Flexible CO2 Sensor Based on the SAW Device

本研究探討利用表面聲波元件為基礎製造出一個行動可撓之薄膜二氧化碳感測器。首先運用溶膠－凝膠法（Sol-Gel Method）調製出氧化鋅（ZnO）溶液並利用旋轉塗佈（Spin Coating）製程進行沉積氧化鋅薄膜並加上三乙醇胺使薄膜更為強健，繼而利用直接噴墨印表技術以奈米銀製作電極，最後再將三乙醇胺以固定的量均勻地塗抹在氧化鋅薄膜最上方作為感測層，而完成此感測器之製作。本研究利用向量網路分析儀（Vector Network Analyzer）量測二氧化碳感測器之頻率響應，結果證明有明顯的感應現象導致訊號偏移。此二氧化碳感測器具有輕薄可攜及可撓之特點，未來將改進製程參數以強化頻率偏移量使增強感測效果。

This study designs and fabricates an inno-vative mobile and flexible CO2 sensor based on the SAW device. The sol-gel method and spin coating are used on the ZnO thin film. In ad-vance, addition of Triethanolamine promotes the robust of ZnO film. Then, the IDT (Inter dig-ital transducer) is designed and fabricated by direct jet-inking technology. Finally, Triethano-lamine film is done as the sensor layer. The center operating frequency of this SAW CO2 sensor is measured by the vector net-work analyzer. The results prove that the signif-icant deviation of frequency resulted from the absorption of CO2 is observed. The characteris-tics of this CO2 sensor is thin, portable and flexi-ble. The improvement of fabricated parameters will enhance the effect of sensing of this saw CO2 sensor in future.