| 초록 |
Humidity sensors are very useful in many industrial and agricultural applications, and they have been getting smaller, cheaper, lighter. There have been many types of humidity sensors such as capacitive, resistive, gravimetric and electromagnetic. Among them, the capacitive and resistive types are popular and the capacitive humidity sensor relies on a change in the permittivity of a polymer dielectric, whereas a resistive sensor responds to a change in electrical resistance with relative humidity. Therefore, to obtain ideal 3-component polyimide capacitive humidity sensor by using various dianhydride monomers a series of humidity sensitive materials were synthesized from 3,3′4,4′-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride(6-FDA), Pyromellitic dianhydride (PMDA), 3,3′,4,4′-benzophenone-tetracarboxylic dianhydride(BTDA) as a dianhydride and p-phenylene diamine(p-PDA), 4,4′-oxydianiline(ODA) as a diamine. |
