Detection of gas atoms with graphene sheets

The potential of single-layered graphene sheets as nano-sensors in detection of noble gases through a wave propagation analysis is investigated using molecular dynamics simulations. An index based on wave velocity shifts in a graphene subjected to an impact of noble gases from an exit aperture is defined and examined to measure the sensitivity of the graphene sensor. The wave velocity shifts are measured by applying a sinusoidal signal to one end of the sheet and acquiring the induced wave signals at two locations on the sheet, i.e. acquiring locations. The simulation results indicate that the nano-sensor is able to differentiate noble gas atoms with a recognizable sensitivity. The dependence of the mass flow rate of gases from the aperture, environmental temperature, and the relative location of the gas exit aperture with respect to the acquiring locations on the sensitivity is studied. The simulation results also show that the resolution of a sensor made of the graphene sheet with a size of 3.62 nm × 15.03 nm can achieve an order of the impact rate of 10−7 femtograms per picoseconds.