Enhancing Humidity Sensing with Functionalized Perylene-Coated Dispense Printed Electrodes: A Comparative Study

Emerging sensing materials are central to improving the functionality and integration of electronic devices. In this study, we report the synthesis of a custom perylene-based organic ligand, <i>N</i>,<i>N</i>'-di-(phenyl-3,5-dicarboxylic acid)-perylene-3,4:9,10-tetracarboxylic acid diimide (PY), which exhibits a strong response to relative humidity (RH). Its sensing performance was systematically compared with that of a commercially available perylene derivative, <i>N</i>,<i>N</i>'-bis-(4-methoxy-benzyl)-perylene-3,4:9,10-bis-(dicarboximide) (PBI). Both materials were deposited onto polyimide substrates with silver-based dispense-printed interdigitated electrodes to fabricate impedimetric sensors. The PY-based sensor demonstrated a high sensitivity of -5289 Ω/% RH at 1 kHz within a 30-90% RH range while exhibiting minimal temperature dependence. In contrast, the PBI-based sensor showed a lower humidity sensitivity of -452 Ω/% RH and a negligible temperature response. This study highlights the potential of functionalized perylene derivatives for developing high performance humidity sensors with minimal thermal interference, eliminating the need for temperature compensation and enabling integration into low power electronic systems. These findings provide valuable insights into molecular design strategies for next-generation environmental monitoring and flexible electronic applications.