Investigation of Manufacturing Impedance-Type Humidity Sensor by the Organic-Inorganic (AMPS/SiO2) Hybrid Material

• Main Authors: Chien-Chang Hung, 洪健彰
• Other Authors: Tsair-Wang Chung
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/71475561312095844467

碩士 === 中原大學 === 化學工程研究所 === 90 === In this study, the impedance-type humidity sensor was prepared by using organic-inorganic composite material and the performance as investigated. The 2-acryl amido-2-methyl-propane sulfonic acid(AMPS) was hybridized in the sol-gel process with silica gel(SiO2). This hybrid material was coated on the Al2O3 substrate with interdigited electrodes by using the spin coating method and was used as a sensing material. The hybrid sensing film could increase the water-resistance and decrease the response time (45s from 95% to 20% RH). On the basis of this study, the better humidity-characteristic device was manufactured by annealing temp of 180℃, thickness of 20μm, and 3.5g hydro-TEOS addition. The impedance varied more than four orders of the magnitude in the range of 35~95% RH under the 1kHz of AC at 25℃. The temperature dependence is only 0.17 %RH/℃ under 15~35℃ and the hysteresis was below 1.5%RH. Furthermore, the surface properties and hybrid structure of the humidity sensor were investigated by using the SEM、TGA and contact angle meter.