Hitachi, Ltd.

Shinyei Kaisha

Nissan Motor Company Limited

Naomasa Sunano

Naotatsu Asahi

Takeshi Fujishiro

Toshio Yoshida

A gas sensor includes a pair of electrodes printed on an electrically insulating substrate, a sensitive layer deposited on tip portions of the electrodes and a part of the substrate adjacent to the tip portions and bridging the space between the electrodes at the tip portion, and a protective film deposited on the electrodes and a part of the substrate adjacent to the tip portion so that a part of each electrode covered with the sensitive layer is free of the protective film. The sensitive layer is formed by depositing titanium oxide by plasma spraying on the substrate, and then heat-treating the deposited titanium oxide, so as to provide a diffusion reactive layer between the sensitive layer and the substrate and to form fine grooves on the surface of the sensitive layer.

Gas sensor and method of producing the same

Gas sensor which is constructed of an electrically insulating base, electrodes formed on said base, and a gas sensitive film formed on the surface of said base at a portion where it detects a gas to be sensed, e.g., an oxygen gas. The gas sensor of the present invention is characterized in that the gas sensitive film is a thermal-sprayed film which is made of an oxide having a perovskite structure. The thermal-sprayed film has its surface formed with fine cracks to have its effective surface area increased so that the response is speeded up. Moreover, the thermal spraying process is so effected during the formation of the oxide film that an impurity to adversely affect the reliability may be avoided from being mixed. The gas sensor may have said gas sensitive film coated with a ceramic material so that is performance may be further improved while protecting the gas sensitive film. Furthermore, it is also effective to add another sensor with the electrically insulating base being commonly used.

Gas sensor

A sensor having an n-type oxide semiconductor layer and a p-type oxide semiconductor layer spaced from and electrically connected in series with each other and two fixed resistors connected in series with each other, wherein the two semiconductor layers and two resistors are connected to construct a four-arm bridge.

Growing community of inventors

Akashi, Japan

Naomasa Sunano