A Novel Structure of Polyimide-Based Humidity Sensor Used in Low Temperature Environment

In this paper, a new structure of polyimide-based humidity sensor is developed, which can work better at low temperature environment. In this humidity sensor, the capacitive part is sputtered on a suspended membrane, the lower electrode is also a controllable heater, used to control the temperature on the surface of the sensor through the external circuits. The results of experiment suggest that the sensor has a wide range of sensing ambient relative humidity from 10%Rli to 90%RH with a controllable constant temperature and at a lower temperature it shows a good linearity.