Surface Acoustic Wave Vapor Sensor with Graphene Interdigital Transducer for TNT Detection

摘要

The performance of the surface acoustic wave (SAW) vapor sensor with graphene interdigital transducer (IDT) is investigated to study the improvement of sensitivity and decrease of secondary effects by the finite element method (FEM). Unlike conventional Al metal electrodes, the observed increase in the SAW phase velocity confirms the existence of elastic loading for the graphene electrode to the contact surface. Accordingly, the mass sensitivity of the SAW device with graphene electrode shows one order of magnitude higher. In the presence of TNT, the resonance frequency shift of the SAW sensor with graphene IDT is approximately 10 times larger than that with Al. Also, graphene electrodes offer the less secondary effects (BAW generations). So the SAW sensor with graphene IDT possesses superior sensing performance.