Abstract: A surface acoustic wave (SAW) sensor includes a surface acoustic wave material and a comb-teeth electrode. The surface acoustic wave material is to be arranged at a place where the surface acoustic wave material is distorted by physical quantity such as stress. The comb-teeth electrode is arranged on the surface of the surface acoustic wave material to excite a surface acoustic wave to the surface acoustic wave material. The surface acoustic wave material has a sapphire board and a ScAlN film arranged on a surface of the sapphire board.

Abstract: A torque sensor includes: a base portion fixed to a metal shaft having a rod shape as a measurement object of strain; a strain detection element of a surface acoustic wave type which is arranged in the base portion, and detects the strain of the metal shaft (10) through the base portion; and a fixing portion that is arranged between the base portion and the strain detection element, and fixes the strain detection element to the base portion.

Abstract: A torque sensor includes: a base portion fixed to a metal shaft having a rod shape as a measurement object of strain; a strain detection element of an surface acoustic wave type which is arranged in the base portion, and detects the strain of the metal shaft (10) through the base portion; and a fixing portion that is arranged between the base portion and the strain detection element, and fixes the strain detection element to the base portion.

Abstract: A surface acoustic wave (SAW) sensor includes a surface acoustic wave material and a comb-teeth electrode. The surface acoustic wave material is to be arranged at a place where the surface acoustic wave material is distorted by physical quantity such as stress. The comb-teeth electrode is arranged on the surface of the surface acoustic wave material to excite a surface acoustic wave to the surface acoustic wave material. The surface acoustic wave material has a sapphire board and a ScAlN film arranged on a surface of the sapphire board.

Abstract: A Fabry-Perot interferometer includes a fixed mirror structure and a movable mirror structure. The fixed mirror structure has a fixed mirror in a spectral region. The movable mirror structure includes a membrane spaced from the fixed mirror structure. The membrane has a movable mirror in the spectral region and multiple springs arranged one inside the other around the spectral region. A spring constant of the inner spring is less than a spring constant of the outer spring. One of the fixed mirror structure and the membrane has multiple electrodes, and the other of the fixed mirror structure and the membrane has at least one electrode that is paired with the electrodes to form opposing electrode pairs arranged one inside the other around the spectral region. The number of the opposing electrode pairs is equal to the number of the springs.

Abstract: A Fabry-Perot interferometer includes a fixed mirror structure and a movable mirror structure. The fixed mirror structure has a fixed mirror in a spectral region. The movable mirror structure includes a membrane spaced from the fixed mirror structure. The membrane has a movable mirror in the spectral region and multiple springs arranged one inside the other around the spectral region. A spring constant of the inner spring is less than a spring constant of the outer spring. One of the fixed mirror structure and the membrane has multiple electrodes, and the other of the fixed mirror structure and the membrane has at least one electrode that is paired with the electrodes to form opposing electrode pairs arranged one inside the other around the spectral region. The number of the opposing electrode pairs is equal to the number of the springs.

Abstract: A temperature sensor includes a semiconductor substrate and a quantum well structural part disposed on the semiconductor substrate. The semiconductor substrate is made of a plurality of elements. The quantum well structural part has a resistance value that changes with temperature. The quantum well structural part includes a plurality of semiconductor layers made of the elements. The semiconductor layers include a plurality of quantum barrier layers and a quantum well layer disposed between the quantum barrier layers. When the semiconductor substrate has a lattice constant “a,” each of the quantum barrier layers has a lattice constant “b,” and the quantum well layer has a lattice constant “c,” the semiconductor substrate, the quantum barrier layers, and the quantum well layer satisfy a relationship of b<a<c or c<a<b.

Abstract: A Fabry-Perot interferometer and a manufacturing method of the same are disclosed. The Fabry-Perot interferometer includes a first mirror structure and a second mirror structure opposed to each other with a gap therebetween. A first mirror and a first electrode of the first mirror structure are electrically insulated from each other, or, a second mirror and a second electrode of the second mirror structure are electrically insulated from each other. In a state of voltage application between the first and second electrode, a distance “dmi” between the first mirror and the second mirror is shorter than a distance “dei” between a first-electrode-inclusive-portion and a second-electrode-inclusive-portion.

Abstract: A gas-sensing semiconductor device 1? is fabricated on a silicon substrate 2? having a thin silicon dioxide insulating layer 3? in which a resistive heater 6 made of doped single crystal silicon formed simultaneously with source and drain regions of CMOS circuitry is embedded. The device 1? includes a sensing area provided with a gas-sensitive layer 9? separated from the heater 6? by an insulating layer 4?. As one of the final fabrication steps, the substrate 2? is back-etched so as to form a thin membrane in the sensing area. The heater 6? has a generally circular-shaped structure surrounding a heat spreading plate 16?, and consists of two sets 20?, 21? of meandering resistors having arcuate portions nested within one another and interconnected in labyrinthine form.

Abstract: A gas-sensing semiconductor device 1? is fabricated on a silicon substrate 2? having a thin silicon dioxide insulating layer 3? in which a resistive heater 6 made of doped single crystal silicon formed simultaneously with source and drain regions of CMOS circuitry is embedded. The device 1? includes a sensing area provided with a gas-sensitive layer 9? separated from the heater 6? by an insulating layer 4?. As one of the final fabrication steps, the substrate 2? is back-etched so as to form a thin membrane in the sensing area. The heater 6? has a generally circular-shaped structure surrounding a heat spreading plate 16?, and consists of two sets 20?, 21? of meandering resistors having arcuate portions nested within one another and interconnected in labyrinthine form.

Abstract: A capacitance type acceleration sensor includes a semiconductor substrate, a weight portion supported with the substrate through a spring portion, a movable electrode integrated with the weight portion, and a fixed electrode cantilevered with the substrate. The movable electrode is displaced along with a facing surface of the movable electrode in accordance with acceleration. The facing surface of the movable electrode faces a facing surface of the fixed electrode so as to provide a capacitor. The capacitance of the capacitor changes in accordance with a displacement of the movable electrode so that an outer circuit detects the acceleration as a capacitance change. Each facing surface of the movable and fixed electrodes has a concavity and convexity portion for increasing the capacitance change.

Abstract: A more reliable gas sensor includes a support film formed on a surface of a substrate and a heater electrode. Surrounding the heater electrode is a heater electrical insulation layer 4. Detection electrodes are formed above the electrical insulation layer. A flat insulating layer is formed over the heater insulation layer, and surfaces of the detection electrodes are exposed and flush with the upper surface of the flat insulating layer. A sensitive film is formed above the flat insulating layer in contact with the surfaces of the detection electrodes. A hollow cavity is formed in the substrate.

Abstract: A capacitance type acceleration sensor includes a semiconductor substrate, a weight portion supported with the substrate through a spring portion, a movable electrode integrated with the weight portion, and a fixed electrode cantilevered with the substrate. The movable electrode is displaced along with a facing surface of the movable electrode in accordance with acceleration. The facing surface of the movable electrode faces a facing surface of the fixed electrode so as to provide a capacitor. The capacitance of the capacitor changes in accordance with a displacement of the movable electrode so that an outer circuit detects the acceleration as a capacitance change. Each facing surface of the movable and fixed electrodes has a concavity and convexity portion for increasing the capacitance change.

Abstract: A capacitance type acceleration sensor includes a semiconductor substrate, a weight portion supported with the substrate through a spring portion, a movable electrode integrated with the weight portion, and a fixed electrode cantilevered with the substrate. The movable electrode is displaced along with a facing surface of the movable electrode in accordance with acceleration. The facing surface of the movable electrode faces a facing surface of the fixed electrode so as to provide a capacitor. The capacitance of the capacitor changes in accordance with a displacement of the movable electrode so that an outer circuit detects the acceleration as a capacitance change. Each facing surface of the movable and fixed electrodes has a concavity and convexity portion for increasing the capacitance change.

Abstract: A flow sensor for detecting flow of fluid includes a thin film portion. The thin film portion has a heater and a detector for detecting temperature around the heater. The heater is made of semiconductor. This flow sensor has high sensor sensitivity with low energy consumption. Further, the sensor has high detection accuracy, and the thin film portion has high endurance. Furthermore, the flow sensor with a passivation film has appropriate thickness so as to improve strength of a thin film portion.

Abstract: An airflow meter has a membrane type sensor element. The sensor element is supported on a support member so that a sensing surface of the sensor element is in parallel to the airflow direction. The airflow meter has at least one means for protecting the sensor element from dust such as foreign particles. The protecting means is provided with an obstruction member that is disposed upstream or downstream of the sensor element with respect to the airflow direction. The sensor element is hidden behind the obstruction member. The obstruction member has gradually spreading surfaces and gradually converging surfaces along the airflow direction. Alternatively, the protecting means can be provided with a deflector, a cover member, a flow guide member, an inlet or a dust collector.

Abstract: An airflow meter has a member that defines a bypass passage. The bypass passage has a sensing passage in which a sensor tip is disposed. The sensing passage is restricted in at least a lateral direction that is a direction perpendicular to both a longitudinal direction of the sensing passage and a perpendicular direction perpendicular to the surface of the sensor tip. This arrangement defines relatively wider distance in the perpendicular direction on the sensor tip.

Abstract: A flow sensor for detecting flow of fluid includes a thin film portion. The thin film portion has a heater and a detector for detecting temperature around the heater. The heater is made of semiconductor. This flow sensor has high sensor sensitivity with low energy consumption. Further, the sensor has high detection accuracy, and the thin film portion has high endurance. Furthermore, the flow sensor with a passivation film has appropriate thickness so as to improve strength of a thin film portion.

Abstract: A capacitance type acceleration sensor includes a semiconductor substrate, a weight portion supported with the substrate through a spring portion, a movable electrode integrated with the weight portion, and a fixed electrode cantilevered with the substrate. The movable electrode is displaced along with a facing surface of the movable electrode in accordance with acceleration. The facing surface of the movable electrode faces a facing surface of the fixed electrode so as to provide a capacitor. The capacitance of the capacitor changes in accordance with a displacement of the movable electrode so that an outer circuit detects the acceleration as a capacitance change. Each facing surface of the movable and fixed electrodes has a concavity and convexity portion for increasing the capacitance change.

Abstract: A thin-film type flow sensor having a thin-film part in which a plurality of patterned resistor films are sandwiched between a pair of insulator films. The resistance ratios among the resistor films are minimized from one sensor to another made from the same wafer. The flow sensor has a lower insulator film, the resistor films, and an upper film laminated in succession on a substrate. The resistor films include a patterned fluid thermometer, a temperature detector, and a heater. The heater has a wiring configuration in which resistor elements are connected in a parallel manner. The wiring widths of the heater and the thermometer can thus be made identical, so that the resistance ratios become invariant over the wafer surface, irrespective of a disparity in etching variations.