Abstract: A transducer includes: a film support portion; a vibration film that is connected to the film support portion and capable of displacing in a thickness direction; a base material having an opposed surface that is opposed to the vibration film; and a first piezoelectric element that is provided with a pair of electrodes and a piezoelectric film sandwiched between the pair of electrodes, and is arranged on the vibration film, in which the transducer maintains a pressure in a space between the base material and the vibration film so as to keep displacement of the vibration film within a certain range.

Abstract: A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively.

Abstract: Disclosed herein is a limiting-current type gas sensor including a solid electrolyte, a first electrode disposed on the solid electrolyte, a second electrode disposed on the solid electrolyte, and a gas feed passage extending between a gas inlet and a first portion of the first electrode, the first portion facing the solid electrolyte. The first electrode is a first porous metal electrode. The gas feed passage is formed of a first porous transition metal oxide having a second melting point higher than a first melting point of the first electrode. The first porous transition metal oxide is Ta2O5, TiO2, or Cr2O3.

Abstract: Disclosed is a thermal flow sensor including a base member and a cover. The base member includes a heater. The cover is formed by an SOI substrate including a silicon substrate, a silicon dioxide film, and a silicon film. The silicon film has a recessed portion defined therein. A main flow passage portion is defined by an exposed surface of the silicon dioxide film which is exposed from the silicon film and which defines a bottom surface of the recessed portion, the silicon film defining a side surface of the recessed portion, and a first principal surface of the cover.

Abstract: Provided is a sensor including a substrate that includes a major surface, a sensor part that includes a gas flow path formed of a porous material, and at least one of a heater or a temperature sensor. The heater is capable of heating the sensor part, the temperature sensor is capable of measuring temperature of the sensor part, the sensor part and the at least one of the heater or the temperature sensor are stacked over the major surface, the at least one of the heater or the temperature sensor is an interconnect having forward tapered side surfaces, and the at least one of the heater or the temperature sensor includes a metal interconnect layer, and the forward tapered side surfaces of the interconnect overlap with the gas flow path in plan view of the major surface.

Abstract: Provided are a heating device and a storage device. The heating device includes a board, and a plurality of microheaters arranged on the board and electrically connected to the board. The plurality of microheaters are arranged in a form of an array. Each of the plurality of microheaters includes a first silicon substrate, an insulating film, and a heater. A first opening portion that penetrates the first silicon substrate along a thickness direction is formed in the first silicon substrate. The insulating film includes a central portion on which the heater is disposed, a peripheral portion disposed on the first silicon substrate, and a connecting portion that connects the central portion and the peripheral portion to each other, and supports the central portion on the first opening portion. The storage device includes a battery pack and the above-described heating device. The board is disposed on the battery pack.

Abstract: Disclosed is a thermal flow sensor including a base member and a cover. The base member includes a heater. The cover is formed by an SOI substrate including a silicon substrate, a silicon dioxide film, and a silicon film. The silicon film has a recessed portion defined therein. A main flow passage portion is defined by an exposed surface of the silicon dioxide film which is exposed from the silicon film and which defines a bottom surface of the recessed portion, the silicon film defining a side surface of the recessed portion, and a first principal surface of the cover.

Abstract: A gas concentration measurement system includes a limiting current-type gas sensor, a voltage source connected to the limiting current-type gas sensor, a current detector connected to the limiting current-type gas sensor, and a gas concentration arithmetic unit connected to the current detector. The voltage source supplies first and second voltages to the limiting current-type gas sensor. The first and second voltages generate first and second limiting currents corresponding to first and second gases, respectively, in the limiting current-type gas sensor. The current detector acquires first and second limiting current values of the limiting current-type gas sensor when the first and second voltages are applied to the limiting current-type gas sensor, respectively.

Abstract: Disclosed herein is a limiting-current type gas sensor including a solid electrolyte, a first electrode disposed on the solid electrolyte, a second electrode disposed on the solid electrolyte, and a gas feed passage extending between a gas inlet and a first portion of the first electrode, the first portion facing the solid electrolyte. The first electrode is a first porous metal electrode. The gas feed passage is formed of a first porous transition metal oxide having a second melting point higher than a first melting point of the first electrode. The first porous transition metal oxide is Ta2O5, TiO2, or Cr2O3.