Strain-Induced Change of Gas Adsorption Properties of Graphene and its Application to a Gas Sensor

The excellent mechanical and electrical properties and gas adsorption ability make graphene a promising candidate for flexible gas sensing material. The strain has been found to change the adsorption energy of gas molecules on graphene surfaces by first-principles calculations. To validate this analysis result, a graphene-based flexible gas sensor was fabricated by transferring graphene onto a soft polymer substrate and the response of the sensor to NO2 molecules was investigated. It was confirmed that graphene shows a repeatable response to this gas. Under the application of bending deformation, the response to 2-ppm NO2 was increased by about 6 times, which strongly indicated the possibility of controlling the gas adsorption behavior of graphene by mechanical strain.