Flexible fuel cell sensors and methods of making and using the same are provided. A fuel cell sensor can be used for the detection of, for example, isopropyl alcohol (IPA), and the working mechanism of the fuel cell sensor can rely on redox reactions. The fuel cell sensor can include a proton exchange membrane (PEM), an anode disposed on a first surface of the PEM, a cathode disposed on a second surface of the PEM opposite from the first surface, and a reference electrode disposed on the first surface of the PEM and spaced apart from the anode.

A ceramic planar sensor element having four contact surfaces and three vias, for example for a lambda sensor. Measures are provided for increasing the loadability of the sensor element in relation to mechanical stresses. The measures relate in particular to the arrangement of the vias and to the design of insulating layers in the interior of the sensor element.

Apparatus and associated methods relate to a one-piece structure for a solid electrolyte chemical sensor (SECS) having a first surface defining a cavity (210, 305, 415) designed to receive a substrate (215, 350, 410) that retains a solid electrolyte (365, 440), an internal water impermeable coating (425) on at least a portion of the first surface, a second surface that is substantially coplanar with an adjacent peripheral edge of a top surface of the substrate (215, 350, 410) when the substrate (215, 350, 410) is received in the cavity (210, 305, 415), and a plurality of electrical contacts (335, 340, 345, 450a-450b) disposed on the second surface adapted to electrically couple with the electrodes (435a-435c) on the substrate (215, 350, 410) when the substrate (215, 350, 410) is received in the cavity (210, 305, 415) and electrical paths are provided between respective electrical contacts (335, 340, 345, 450a-450b) and electrodes (435a-435c).

An electrochemical gas sensor (1) having a stacked assembly of at least one first electrode (3) and a second electrode (6), which are respectively arranged on a carrier membrane (2, 5), and a separator (4) arranged between the electrodes (3, 6), including a gas conduction path (14) between the first electrode (3) and the second electrode (6). The gas conduction path (14) is constituted within the structural space defined by the electrodes (3, 6).

A method for manufacturing a sensor element that includes: a pair of electrodes; a ceramic layer having a hollow space that is to be an air introduction hole; and a first layer and a second layer stacked at both surfaces of the ceramic layer, One of the electrodes is in communication with the hollow space, The method includes: preparing an unsintered ceramic sheet, and a burn-out material sheet having a thickness different from that of the unsintered ceramic sheet, the burn-out material sheet having, in a plane orthogonal to the direction of an axial line O, a cross-sectional area substantially identical to a cross-sectional area of the pre-sintering hollow space; placing the burn-out material sheet in the pre-sintering hollow space; pressing the sheets so as to have an identical thickness; and burning out the burn-out material sheet.

A deterioration determination apparatus is usable with an ammonia sensor that includes an ammonia element portion that includes, a solid electrolyte, an ammonia electrode, and a reference electrode. The deterioration determining apparatus compares a first evaluation value and a second evaluation value, and determines whether deterioration has occurred in the ammonia element portion of the ammonia sensor at an evaluation time or subsequent to the evaluation time. The first evaluation value is based on a first sensor current obtained when a DC voltage is applied between the ammonia electrode and the reference electrode of the ammonia element portion at an initial time that is during an initial use period of the ammonia sensor. The second evaluation value is based on a second sensor current obtained when the DC voltage is applied between the ammonia electrode and the reference electrode subsequent to the initial period of use of the ammonia sensor.

A gas sensor includes a sensor element, a detection device, a reference gas regulating device. The sensor element includes an element body having disposed therein a measurement-object gas flow section, a measurement-object-gas-side electrode disposed in or out of the element body, a reference electrode disposed within the element body, and a reference gas introducing section that allows a reference gas to be introduced thereinto and to flow therethrough to the reference electrode. The reference gas regulating device allows an oxygen pump-in current to flow between the reference electrode and the measurement-object-gas-side electrode to pump oxygen into around the reference electrode from around the measurement-object-gas-side electrode. A ratio R1/R2 of a reaction resistance R1 of the reference electrode to a diffusion resistance R2 of the reference gas introducing section is greater than or equal to 0.1 and less than or equal to 2.0.

A limiting current-type gas sensor element including a plurality of stacked ceramic layers and configured to output a limiting current value which depends on a concentration of a specific gas in a gas to be measured when a certain voltage is applied. The gas sensor element includes a solid electrolyte member having oxygen ion conductivity; a heater that heats the solid electrolyte member; a measurement electrode and a reference electrode provided on the solid electrolyte member; a chamber facing the measurement electrode and into which the gas to be measured is introduced; a gas inlet located to a tip side of the chamber in a longitudinal direction; and a diffusion resistance part provided in the gas inlet. A heating center of the heater is located further to the tip side than an electrode center of the measurement electrode is.

A gas sensor includes: a substrate; an insulating layer arranged over the substrate; and a solid electrolyte layer, wherein the substrate is formed with a cavity that penetrates the substrate in a thickness direction of the substrate, wherein the insulating layer has a peripheral portion arranged over the substrate around the cavity, and a membrane portion which is located over the cavity and is connected to the peripheral portion, wherein the membrane portion includes a movable portion, wherein a through-hole, which penetrates the membrane portion around the movable portion in the thickness direction, is formed such that the movable portion is capable of being displaced along the thickness direction, and wherein the solid electrolyte layer is arranged over the movable portion.

There is provided a carbon dioxide gas sensor that includes a flow path including an inlet into which a detected target gas is introduced; and a first element and at least one second element arranged in the flow path. The first element includes a first solid electrolyte layer, a first cathode, and a first anode, the first solid electrolyte layer being interposed between the first cathode and the first anode. The at least one second element includes a second solid electrolyte layer, a second cathode, and a second anode, the second solid electrolyte layer being interposed between the second cathode and the second anode. The first solid electrolyte layer and the second solid electrolyte layer are formed of an oxygen ion conductor. The first cathode is inside the flow path. The second cathode and the second anode are inside the flow path and outside the flow path, respectively.