Palladium nanopartcle coated tobacco moasic virus sensing layer based surface acoustic wave hydrogen sensors

We describe ongoing research aimed at investigating the role of engineered nanomaterials in designing SAW resonator based gas sensors. We investigated the use of Pd-cluster coated, engineered tobacco mosaic virus as sensing material for the development of hydrogen sensors using 315 MHz surface acoustic wave (SAW) two-port resonators. Absorption and desorption of hydrogen from the sensing layer causes the SAW devices to be perturbed. This perturbation results in variation of wave velocity and hence resonant frequency of the device that can be calibrated to determine the concentration of hydrogen. The sensor showed repeatable performance when tested over a range of concentration from (0.2-2.5%) hydrogen with low response times (30sec). High robustness and stability of film was observed when tested continuously over a range of concentrations and long durations. The sensor was seen to respond by producing a hydrogen concentration independent increase in frequency opposite to the more common mass loading behavior characterized by decreases in frequency.