High-Sensitivity and Low-Hysteresis Porous MIM-Type Capacitive Humidity Sensor Using Functional Polymer Mixed with titanium dioxide Microparticles

摘要

The present invention relates to a high-sensitivity and low-hysteresis porous metal-insulator-metal (MIM) type capacitive humidity sensor using a functional polymer mixed with a titanium dioxide microparticle, which improves characteristics of a MIM type capacitive humidity sensor using a functional polymer mixed with a titanium dioxide microparticle and a porous upper electrode, and realizes high sensitivity, low hysteresis, a quick response time, and a wide humidity detection range. According to the present invention, the humidity sensor comprises: an optimally designed porous upper electrode; a functional polymer humidity detection layer; a lower electrode; and a glass substrate. The porous upper electrode is designed to increase a contact area between the detection layer and steam, thereby providing the high sensitivity and the quick response time. The functional polymer mixed with a titanium dioxide microparticle has excellent low hysteresis characteristics in a wide humidity detection range and has excellent long-term stability. The humidity sensor provides the high sensitivity of 0.85 pF/%RH and the quick response time of below 35 seconds when relative humidity reaches 90 %RH from 10 %RH. Moreover, the humidity sensor has ultralow hysteresis of 0.95 %RH at 60 %RH, excellent temperature dependency, and a stable capacitance value of an error rate of 0.17% as maximum during a continuous test of 120 hours.