An Improved Humidity Sensor with GO-Mn-Doped ZnO Nanocomposite and Dimensional Orchestration of Comb Electrode for Effective Bulk Manufacturing

Abstract

The measurement and control of humidity is a major challenge that affects the sensing properties of sensors used in high-precision equipment manufacturing industries. Graphene Oxide(GO)-based materials have been extensively explored in humidity sensing applications because of their high surface area and functional groups. However, there is a lack of effective bulk-manufacturing processes for the synthesis of 2D-based nanocomposites with comb electrodes. Moreover, water intercalation within the layers of 2D materials increases recovery time. This work demonstrates the enhanced sensing characteristics of a capacitive/resistive GO-MnZnO nanocomposite humidity sensor produced using a cost-effective single-pot synthesis process. The in-plane sensing layer consistently improves sensitivity and reduces response time for a wide range of relative humidity measurements (10% to 90%). Interdigitated gold electrodes with varying numbers of fingers and spacing were fabricated using photolithography on a Si/SiO₂ for a consistent sensor device platform. The choice of nanomaterials, dimension of the sensor, and fabrication method influence the performance of the humidity sensor in a controlled environment. GO nanocomposites show significant improvement in response time (82.67 times greater at 40% RH) and sensitivity (95.7 times more at 60% RH). The response time of 4.5 s and recovery time of 21 s was significantly better for a wider range of relative humidity compared to the reduced GO-sensing layer and ZnMnO. An optimized 6 mm × 3 mm dimension sensor with a 28-fingers comb was fabricated with a metal-etching process. This is one of the most effective methods for bulk manufacturing. The performance of the sensing layer is comparable to established sensing nanomaterials that are currently used in humidity sensors, and hence can be extended for optimal bulk manufacturing with minimum electrochemical treatments.

Improved humidity sensing performances of boron doped ZnO nanostructured thin films depending on boron concentration

“…The RH in the humidity test chamber was provided by atomized water (wet air) produced by a desktop humidifier. The processes of introducing the produced wet air into the humidity test chamber, controlling the RH percentage, and removing the wet air from the chamber were carried out with a computer-controlled Arduino-based automatic feedback controller [50]. In this way, possible fluctuations/variations of the humidifier used were minimized and measurements were made in a more controlled manner.…”

Advances in graphene-based 2D materials for tendon, nerve, bone/cartilage regeneration and biomedicine

“…For example, at 40% relative humidity (RH), the response time of GO nanocomposite is 82.67 times that of normal conditions, and its sensitivity is 95.7 times that of normal conditions at 60%RH. 125 Wang et al. found that the GO humidity sensor has a frequency change of 103 kHz/%RH at low humidity (30–60%RH).…”

Capacitive Humidity Sensor with a Rapid Response Time on a GO-Doped P(VDF-TrFE)/LiCl Composite for Noncontact Sensing Applications

“…These properties make GO potentially useful as a sensing material. Further, GO is more compatible with polymers than pure graphene, and it is a good candidate for chemical sensing applications [24][25][26][27][28].…”