Design and fabrication of micro hydrogen gas sensors using palladium thin film

► A highly sensitive hydrogen gas sensor of the multi-layer, micro heater type was designed and fabricated using a MEMS process. ► A Pd thin film was fabricated by R.F. magnetron sputtering. ► The electrothermal properties of the designed H2 sensor were analyzed by the finite elements method. ► The sensing properties of the hydrogen sensor were optimized at a heater voltage of 4.0 V to give sensitivity of 0.267% to hydrogen gas at 500 ppm. ► The gas sensitivity was positively correlated with the hydrogen concentration.