There’s an interesting article recently published about using graphene, or carbon nanotubes, in ammonia sensors. The basic idea is that the presence of NH3 molecules changes the conductance of the graphene sheet or the carbon nanotube. The article develops an analytical model for the conductance, and compares it with experimental data for carbon nanotubes.

Here is the reference: Elnaz Akbari, Vijay K. Arora, et al (6 others), “An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH3 gas sensor applications”, Beilstein Journal of Nanotechnology, 2014, vol 5, pp 726-734. URL is http://www.beilstein-journals.org/bjnano/content/pdf/2190-4286-5-85.pdf (free access).

The first two figures of that article are understandable for schoolchildren, and I plan to show them to some youngsters when we meet for our next science discussion. It will be a good visual introduction to the topic of how sensors work.

The article thereafter gets quite mathematical and detailed — too…