A sensor element includes an element body and a porous protective layer arranged to cover a part of a surface of the element body. The protective layer includes an inlet protective layer arranged to cover a gas inlet formed in the surface of the element body, and at least a part of a face included in the surface of the element body, the face on which the gas inlet is opens, and an arithmetic average roughness Rap of an inner peripheral surface of an internal space of the inlet protective layer satisfies at least one of conditions below: the arithmetic average roughness Rap is 8 μm or more, and the arithmetic average roughness Rap is higher than an arithmetic average roughness Rac of a bonding surface of the protective layer, the bonding surface at which the protective layer is bonded to the element body.

A sensor element includes an element body having a measurement-object gas flow section formed therein, and a porous protective layer arranged to cover first to fifth surfaces of the element body. When an external wall that is the thinnest of parts of an external wall which constitute the element body and extend from the measurement-object gas flow section to the first to fifth surfaces is defined as a thinnest external wall and a surface corresponding to the thinnest external wall is defined as a closest surface, a part of the protective layer which covers the closest surface overlaps the entirety of the thinnest external wall when viewed in a direction perpendicular to the closest surface, and has one or more internal spaces formed therein which overlaps 80% or more of the thinnest external wall when viewed in the direction perpendicular to the closest surface.

A sensor element including a first ceramic layer (105), and a measurement electrode (110a) and a reference electrode (108a) disposed thereon, further comprising a through hole (105a) formed in the first ceramic layer, a through hole conductor (121c), a reference lead (108b) connected to the reference electrode and connected to the through hole conductor, and a second ceramic layer (103) disposed to face the first ceramic layer, the sensor element further including a gas flow chamber (130) provided between the first and second ceramic layers, and facing the through hole and being in communication with the reference lead, and a gas flow passage (170) open to a second region (100s) of an outer surface of the sensor element, thereby establishing communication between the gas flow chamber and an outside atmosphere. Also disclosed is gas sensor including the gas sensor element and a method for manufacturing the gas sensor element.

An electrochemical sensor, including a working electrode, a reference electrode, and a counter electrode. The working electrode may include a transition metal, and is contacted with a solution including an alkaline media for oxidation of the transition metal, such that the sensor may be used to provide data to quantify the amount of a pathogen in the solution. In certain embodiments, the transition metal of the working electrode is nickel. In other embodiments, the working electrode includes graphene-layered nickel. And, in certain embodiments, the working electrode may be a rotating disk electrode, wherein the working electrode rotates in a solution including an alkaline media.

Embodiments relate generally to systems, devices, and methods for depositing an electrode and an electrolyte on a microelectromechanical system (MEMS) electrochemical sensor. A method may comprise providing a blade on a surface of a substrate; providing a ridge along the perimeter of the substrate; pressing the electrode and the electrolyte onto the blade and the ridge; cutting the electrode into multiple electrodes; positioning the electrolyte to contact the surface, the blade, and the ridge; and positioning the multiple electrodes to contact the surface, the blade, and the ridge.

A gas sensor which detects a concentration of a specific gas contained in a gas to be measured is provided with a gas sensor element. The gas sensor element has an ion conductive solid electrolyte body, a measuring gas electrode which is mounted on a surface of the solid electrolyte body, a reference gas electrode mounted on a surface of the solid electrolyte body, and a catalyst layer mounted on an outer-side relative to the measuring gas electrode-side. The catalyst layer contains a metal catalyst loaded onto a carrier. The metal catalyst is a Pt single substance, and has a specific surface area defined by the equation below of equal to or more than 0.01 to equal to or less than 23: Specific surface area=total surface area of metal catalyst which exists on an electrode unit surface area/actual surface area of electrode per electrode unit surface area.

An amperometric electrochemical sensor for measuring the concentrations of one or more target gas species in a gas sample or gas stream, the sensor having at least one electrochemical cell with first and second surface electrodes, an electrolyte layer and a passive signal amplifying layer (“SAL”) comprising electrically conductive material like platinum, wherein at least a portion of the electrolyte layer is located between the surface electrodes and the SAL such that the SAL is in direct, conductive contact with the electrolyte layer but is not in direct contact with the surface electrodes. Sensor systems and detection methods are also provided.

A sensor element for detecting a specific gas concentration in a measurement-object gas includes: an element body including an oxygen-ion-conductive solid electrolyte layer, and having inside a measurement-object gas flow portion that introduces and flows a measurement-object gas and a reference gas chamber used to store a reference gas that is a reference for detecting a specific gas concentration; a reference electrode disposed in the reference gas chamber; and an electrically conductive portion which includes a reference electrode terminal and a reference electrode lead portion that provides electrical continuity between the reference electrode terminal and the reference electrode. The reference gas chamber is provided inside the sensor element in an isolated form, and at least part of the electrically conductive portion is densely formed so as to block movement of oxygen between the reference gas chamber and the outside of the sensor element via the electrically conductive portion.

A sensor element includes: a plurality of internal spaces which sequentially communicate from a gas inlet, and in which respective inner electrodes are arranged; an outer electrode; a porous body region covering the outer electrode; and a plurality of electrochemical pump cells capable of pumping in or out oxygen between the internal spaces and an outside, and a ratio A/B is 0.07 or more, where A is a magnitude of a limiting current when a main pump cell including a main pump electrode in a first internal space located closest to the inlet and the outer pump electrode pumps in oxygen to the first internal space in a case where a pump in current evaluation gas is introduced, B is a magnitude of a limiting current when oxygen is pumped out from the first internal space in a case where a pump-out current evaluation gas is introduced.

In a method for manufacturing an electrochemical gas sensor for sensing a target gas, a semi-manufactured gas sensor is provided. The semi-manufactured gas sensor comprises a substrate supporting an arrangement comprising a thin film of a thickness s≤5 pm arranged between a sensing electrode configured to chemically interact with the target gas and a reference electrode facing the substrate. The thin film is an electronically non-conducting and ionically non-conducting ceramic or glass. The arrangement then is heated to an annealing temperature for irreversibly turning the thin film into an ionic conductor by incorporating mobile ions released from the sensing electrode in response to the heating.