P3HT and PEDOT:PSS printed thin films on chemiresistors: An economic and versatile tool for ammonia and humidity monitoring applications.

We hereby present the fabrication of simple and efficient humidity and ammonia sensors based on a chemiresistor design employing a differential measurement technique. Interdigitated electrodes are connected via PEDOT:PSS or P3HT polymers and a reproducible and scalable fabrication procedure is presented. This procedure utilizes pneumatic nozzle printing instead of drop or spin‐based processes and includes an optimized encapsulation procedure and material for sealing the reference electrodes. The suitability of the NH3 sensor for quantifying ammonia in a range of 2 to 100 ppm within a period of several months is furthermore presented. The developed humidity sensor is operational for several months in a humidity range between 10 and 60% RH. Once this range is exceeded, a sensor decay by irreversible saturation can be observed. Based on the low fabrication costs of the sensors (~0.5 $ when ordering 1000 pcs of the platform + printing work), they provide a very attractive tool for industrial humidity and ammonia sensing applications. [ABSTRACT FROM AUTHOR]