PEDOT:PSS modified Screen Printed Graphene-Carbon Ink based Flexible Humidity Sensor

Abstract

In this work, we present a screen-printed humidity sensor fabricated on a flexible polyvinyl chloride (PVC) substrate. A comparative analysis has been carried out for printed graphene-carbon electrode with and without Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) modification in the humidity sensing range of 25 -90 %RH. The sensor modified with PEDOT:PSS demonstrated enhanced performance ( ~ 1 %/%RH versus ~ 0.8 %/%RH of unmodified sensor). Further, the enhancement in the performance of the modified sensor was found to be prominent in the low to moderate humidity range (≤60 %RH). The repeatability, response and recovery time were also analysed for both types of sensors and their applicability has been demonstrated for neonatal care by monitoring the humidity level of a wet baby diapers. This demonstration shows the potential application of presented humidity sensors in areas such as environmental monitoring, healthcare, industrial, and agriculture.

PEDOT:PSS-Coated Screen-Printed Graphene–Carbon Ink-Based Humidity and Temperature Sensor

“…The printing of biocompatible G-C ink for electrodes is resource efficient methods as compared to conventional metal deposition > REPLACE THIS LINE WITH YOUR MANUSCRIPT ID NUMBER (DOUBLE-CLICK HERE TO EDIT) < methods. The work presented in this paper extends our preliminary results presented at IEEE International Conference on Flexible and Printable Sensors and Systems (FLEPS) 2022 [44]. Here, we have discussed the influence of the operating temperature on humidity sensing characteristics of PEDOT:PSS coated/modified G-C ink-based sensor.…”

“…The comparative analysis of humidity sensing performance, displayed in Fig. 2(c) [44], clearly shows the enhanced performance of sensor2 as compared to sensor1, specifically for low to moderate humidity range (below and around 60 %RH). The reproducibility analysis was also carried out for sensor2 by repeating the fabrication route and developing replica sensors (RS).…”

“…The humidity sensing characteristics for both sensor types i.e., sensor1 (pre-modification G-C layer) and sensor2 (PEDOT:PSS coated/modified G-C layer) was observed in 25 -90 %RH humidity range at room temperature (27 ºC ± 2 ºC) and the results are shown in Fig. 2 (a-b) [44]. The humidity sensing performance is examined using % response, which is determined as follows [45]:…”

“…Dynamic response characteristics of (a) sensor1 and (b) sensor2. (c) % Response for sensor1 and sensor2 [44].…”

PEDOT:PSS-Based Disposable Humidity Sensor for Skin Moisture Monitoring

“…The PEDOT:PSS is selected as sensing material considering its excellent humidity sensing properties, biocompatible nature, good thermal stability and compatibility towards solution based processes [25]. The choice of PEDOT:PSS sensing layer in combination with G-C IDEs is encouraged from our previous work [26]. Further, paper is selected as a substrate because it is recyclable, disposable, and easily available.…”