$SnO_2$ gas sensors(thin/thick film) were fabricated on the $Al_2O_3$ and Si substrates. The effect of electrode design on the $H_2$ gas sensitivity was investigated as a function of width, and overlapped length of electrode. The gas sensitivity was measured under the $H_2$ gas mixed with synthetic air as the carrier gas.
The $H_2$ gas sensitivity was strongly influenced by the gas sensor electrode design. The critical sensitivities between thick film sensor and thin film sensor were observed to be different. In case of thin film gas sensor, there was a certain width that showed the maximum gas sensitivity, and $H_2$ gas sensitivity increased as the overlapped length of electrode increased. In case of thick film gas sensor, $H_2$ gas sensitivity increased as the electrode width increased, and overlapped length of electrode decreased.
