An inkjet-printed humidity sensor based on SiO2 nano particle blended PEDOT:PSS films

In this paper, a low cost and low power consumption humidity sensor was developed by blending SiO₂ nano-particles blending with PEDOT conductive polymers. The developed sensing material was fabricated by inkjet-printing technology on silicon substrate. Compared with pristine PEDOT:PSS materials, the adding of SiO₂ nano-particles improves the sensitivity of humidity with a factor of 2. The time response of the developed sensing material was also examined to evaluate its sensing stabilities. At the same time, the sensor selectivity to humidity, CO2, and NO was also experimentally tested. This work developed a promising inkjet-printable humidity sensing materials for various applications.