Hitachi, Ltd, has developed a high performance hydrogen sensor, which is of the Si-MOSFET type.
A thin-film lamination structure made of platinum (Pt) and titanium (Ti) is uniquely used for the sensor part (gate) of the hydrogen sensor.
Many beneficial features:
The new sensor is capable of sensing hydrogen having a concentration of 1000 ppm or higher in about 1 second.
The sensor is highly resistive to heat and humidity.
Its lifetime is 3 year or longer, showed by the lifetime acceleration test.
The semiconductor manufacturing equipment, currently used, may be used for manufacturing the sensor. The sensors can be mass-produced.
A size of the sensor part is 2.0mm x 2.0 mm.
Threshold voltages of the sensors manufactured are little varied in value.
The sensor exactly responds the hydrogen concentration.
Temperature required for accelerating the reaction is about 100oC, lower than that of the ceramic sensor, currently and widely used.
This indicates that power consumption (1000 mW) by the sensor is low.
The explosion-proof structure for the sensor is simple, leading to size reduction.