2009/02/10 by Mao-Chen Liu, Ching‐Liang Dai, Chih-Hua Chan +1 · 1 citation
Chemical Engineering · Engineering · Materials Science · #Analytical Chemistry and Sensors #Conducting polymers and applications #Gas Sensing Nanomaterials and Sensors
paper · pdf · doi:10.3390/s90200869
openalex publication_date 2009/02/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
This study presents the fabrication of a polyaniline nanofiber ammonia sensor integrated with a readout circuit on a chip using the commercial 0.35 μm complementary metal oxide semiconductor (CMOS) process and a post-process. The micro ammonia sensor consists of a sensing resistor and an ammonia sensing film. Polyaniline prepared by a chemical polymerization method was adopted as the ammonia sensing film. The fabrication of the ammonia sensor needs a post-process to etch the sacrificial layers and to expose the sensing resistor, and then the ammonia sensing film is coated on the sensing resistor. The ammonia sensor, which is of resistive type, changes its resistance when the sensing film adsorbs or desorbs ammonia gas. A readout circuit is employed to convert the resistance of the ammonia sensor into the voltage output. Experimental results show that the sensitivity of the ammonia sensor is about 0.88 mV/ppm at room temperature.