Hydrogen detecting characteristics and an improved algorithm for data transmission of a palladium nanoparticle/amorphous InGaZnO thin film based sensor

Hydrogen gas detecting properties of a new sensing device have been comprehensively investigated and reported. The proposed sensor is synthesized by a sputtered amorphous InGaZnO (a-IGZO) thin film and thermally evaporated palladium (Pd) nanoparticles (NPs) onto a sapphire substrate. The use of Pd NPs can efficiently enhance the surface area/volume (SA/V) ratio and catalytic activity of Pd metal which yields the significant improvement on hydrogen sensing performance. The material properties related the elemental composition, height profile, surface and cross-section images have been carefully characterized. Experimentally, good hydrogen detecting behaviors including an ultra-high sensing response of 6.4×105 under introduced 1% H2/air gas with a short response (recovery) time of 3 s (11 s) and a very low detecting level of 10 ppb H2/air at 275 ℃ are acquired. The proposed sensor device exhibits good selectivity toward hydrogen gas. Novel GPFDM model is used to reduce redundant data and improve the data transmission efficiency for Internet of Things (IoT) application. The proposed algorithm uses preprocessing along with adjustable thresholds. Experimentally, the GPFDM method can effectively improve transmission efficiency without increasing computational complexity. The GPFDM method shows a prominent reduced data percentage (RDP) of 84.42% and a mean absolute percentage error (MAPE) only of 0.59% compared to the original transmitted data.