All printed full range humidity sensor based on Fe2O3

Accurate and quantifiable detection of humidity levels in the environment, poses a challenge in domain of printed electronics. Especially for, the enhancement of sensor sensitivity and reproducibility which depends on various fabrication procedures and material selections. In order to fabricate stable and reproduceable sensor with all range humidity detection, this work presents a flexible humidity sensor using inter digital electrodes (IDEs) and employing Iron Oxide (Fe2O3) nanoparticle ink as a sensing layer. The IDEs are printed using an inkjet printer DMP-3000 with finger width and spacing of 100 mu m and the active layer is fabricated using a spin coater. The overall dimensions of the achieved sensor are similar to 11 mm x 7 mm length and width, respectively. The impedance, capacitance, frequency, and sheet resistance parameters of the proposed sensor were measured in an airtight homemade test setup from 0-100% relative humidity (RH). The proposed sensor shows a fast response and recovery time of similar to 1.79 s and similar to 4.97 s, respectively. Hence, the proposed results demonstrate a highly stable sensor, which is capable of detecting change in humidity for real time environmental monitoring applications. (C) 2020 Elsevier B.V. All rights reserved.