Graphene-based sensor has potential for high-resolution thermal imaging

The unique electronic properties of graphene can be harnessed in a sensor that could be used for highly sensitive security screening to detect explosives and other hazardous substances, according to research from the Cambridge Graphene Centre. Combining the single-atom-thick carbon with pyroelectric materials, which generate electric fields when heated or cooled, the team has produced a sensor that can detect temperature changes down to a few tens of µK.

The research was part of a European consortium known as the Graphene flagship, which aims to commercialise graphene applications within 10 years. In a paper in Nature Communications, the team describes devices based on pyroelectric substrates onto which a graphene layer is deposited. On top of this is placed a type of electrode known as a ‘floating gate’, which concentrates the temperature change-induced electric field produced by the substrate onto the graphene. This changes the electrical resistance of the material, which is measured as the device output. Devices that measure changes in resistance due to heating are known as bolometers, and the team claims that the combination of pyroelectricity and bolometer activity means that these sensors could be used as pixels in a high-resolution thermal imaging camera.