NO2 and NH3 Sensing Characteristics of Inkjet Printing Graphene Gas Sensors.

Caterina Travan,Alexander Bergmann

doi:10.3390/s19153379

Abstract

Graphene is a good candidate for filling the market requirements for cheap, high sensitivity, robust towards contamination, low noise, and low power consumption gas sensors, thanks to its unique properties, i.e., large surface, high mobility, and long-term stability. Inkjet printing is a cheap additive manufacturing method allowing fast, relatively precise and contactless deposition of a wide range of materials; it can be considered therefore the ideal technique for fast deposition of graphene films on thin substrates. In this paper, the sensitivity of graphene-based chemiresistor gas sensors, fabricated through inkjet printing, is investigated using different concentrations of graphene in the inks. Samples have been produced and characterized in terms of response towards humidity, nitrogen dioxide, and ammonia. The presented results highlight the importance of tuning the layer thickness and achieving good film homogeneity in order to maximize the sensitivity of the sensor.

Highlights

Good breathing air quality is one of the most important factors for a healthy life
Increasing consciousness within the population and institutions is translating into a substantial increase in the demand for cheap, low power, high sensitivity, and reliable gas sensors for monitoring the concentration of pollutants in indoor and outdoor environments
A better alternative might be represented by the use of graphene-based electrochemical gas sensors

Summary

Introduction

Increasing consciousness within the population and institutions is translating into a substantial increase in the demand for cheap, low power, high sensitivity, and reliable gas sensors for monitoring the concentration of pollutants in indoor and outdoor environments. Gas sensors partially filling these market’s requirements are MOX (metal oxide) or polymer based chemiresistor gas sensors [1,2,3]. Such sensors present several disadvantages: They require high operating temperatures (up to 600 ◦ C) due to slow desorption characteristics, are sensitive towards humidity and show baseline drift, which require frequent re-calibration [2,4,5,6]. Graphene offers high sensitivity and fast response time thanks to its two-dimensional structure and low noise due to its high conductivity [7,8,9,10,11,12]

Methods

Discussion

Conclusion