The moisture sensor is based on resistance change in the IDE structure. For the prototyped humidity sensors, a resistance change of more than 20% was observed while monitoring a moisture increase of 15% at room temperature. The resistance changes were displayed on an LCD panel and on a laptop computer using LabView software. The temperature sensor was also based on the resistance change of the IDE structure. A resistance change of more than 2% was observed when the sensor was exposed to a temperature increase of 10°C from room temperature. The display is similar to that of the moisture sensor. To decouple the temperature signal from the humidity signal, an integrated sensor platform was designed and tested. Preliminary investigations showed that the humidity signal could be decoupled from the temperature signal completely. A totally different integrated structure was designed to decouple the humidity signal from the temperature signal. Additional IDE structures will be printed, and the integrated sensing elements will be tested in an environmental chamber to measure sensitivity and repeatability by varying the relative humidity and temperature separately and simultaneously.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2013: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: May 12, 2013
Pages: 84 - 87
Industry sector: Sensors, MEMS, Electronics
Topics: Printed & Flexible Electronics