University of California

Los Alamos National Security, LLC

Triad National Security, LLC

Eric L Brosha

Fernando H Garzon

Rangachary Mukundan

Christopher J Romero

Mahlon Scott Wilson

Brandon W Chung

Ian D Raistrick

Cortney Kreller

Cortney R Kreller

Kannan Ramaiyan

Tommy Rockward

A multi-electrode sensor array includes a substrate and n test couples on the substrate, wherein n is an integer of 2 or greater. Each test couple includes a pseudo-reference electrode and a sensing electrode including a material capable of oxidizing or reducing a gas of interest. A solid electrolyte layer that is common to and continuous over the n test couples may cover at least a portion of each pseudo-reference electrode and at least a portion of each sensing electrode. At least one of the n test couples may include an initial test couple and one or more duplicates thereof connected in electrical series, and a mixed potential may be measured across the electrical series. When multiple electrodes having different electrocatalytic activities are combined in the array of n test couples, mixed potential data from the array may be mathematically processed to accurately measure gas concentrations in a mixed-gas environment. The electrodes may be designed and arranged to increase the selectivity and sensitivity of the multi-electrode sensor array.

Solid state multi-electrode sensor array for real-time monitoring of multi-gas mixtures

A fuel contamination detection system includes a fuel quality analyzer, a multiway valve, and a controller. The multiway valve includes a first inlet, a second inlet, and an outlet. The multiway valve also may include a switching device. The controller is electrically coupled to the analyzer. The controller may be coupled to the switching device, if present. Fuel is flowed through the fuel quality analyzer and an output current is measured to determine whether the fuel includes impurities. The controller is operable to signal a fuel dispensing system to dispense fuel if the fuel is sufficiently clean or cease dispensing fuel if the fuel is impure.

System and method for detection of impurities during refueling

A fuel quality analyzer for detecting contaminants in a fuel supply includes an anode flow field plate defining a first fuel flow field channel and a fuel inlet port, a cathode flow field plate defining a second fuel flow field channel and a fuel outlet port, a polymer electrolyte membrane between the anode and cathode flow field plates, a first electrode between the anode flow field plate and the polymer electrolyte membrane, and a second electrode between the cathode flow field plate and the polymer electrolyte membrane. The second electrode has a higher platinum loading than the first electrode. A reservoir volume is defined by the anode and cathode flow field plates. At least a portion of the polymer electrolyte membrane extends into the reservoir volume. The reservoir volume is configured to retain water to humidify the polymer electrolyte membrane.

Hydrogen fuel quality analyzer with self-humidifying electrochemical cell and methods of testing fuel quality

A method of making electrochemical sensors in which an electrolyte material is cast into a tape. Prefabricated electrodes are then partially embedded between two wet layers of the electrolyte tape to form a green sensor, and the green sensor is then heated to sinter the electrolyte tape around the electrodes. The resulting sensors can be used in applications such as, but not limited to, combustion control, environmental monitoring, and explosive detection. A electrochemical sensor formed by the tape-casting method is also disclosed.

Tape-cast sensors and method of making

A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

Thin film mixed potential sensors

A mixed potential electrochemical sensor for the detection of gases has a ceria-based electrolyte with a surface for exposing to the gases to be detected, and with a reference wire electrode and a sensing wire electrode extending through the surface and fixed within the electrolyte as the electrolyte is compressed and sintered. The electrochemical sensor is formed by placing a wire reference electrode and a wire sensing electrode in a die, where each electrode has a first compressed planar section and a second section depending from the first section with the second section of each electrode extending axially within the die. The die is filled with an oxide-electrolyte powder and the powder is pressed within the die with the wire electrodes. The wire-electrodes and the pressed oxide-electrolyte powder are sintered to form a ceramic electrolyte base with a reference wire electrode and a sensing wire electrode depending therefrom.

Electrodes for solid state gas sensor

A hydrocarbon sensor is formed with an electrolyte body having a first electrolyte surface with a reference electrode depending therefrom and a metal oxide electrode body contained within the electrolyte body and having a first electrode surface coplanar with the first electrolyte surface. The sensor was formed by forming a sintered metal-oxide electrode body and placing the metal-oxide electrode body within an electrolyte powder. The electrolyte powder with the metal-oxide electrode body was pressed to form a pressed electrolyte body containing the metal-oxide electrode body. The electrolyte was removed from an electrolyte surface above the metal-oxide electrode body to expose a metal-oxide electrode surface that is coplanar with the electrolyte surface. The electrolyte body and the metal-oxide electrode body were then sintered to form the hydrocarbon sensor.

Method for forming a potential hydrocarbon sensor with low sensitivity to methane and CO

A solid state gas sensor generates an electrical potential between an equilibrium electrode and a second electrode indicative of a gas to be sensed. A solid electrolyte substrate has the second electrode mounted on a first portion of the electrolyte substrate and a composite equilibrium electrode including conterminous transition metal oxide and Pt components mounted on a second portion of the electrolyte substrate. The composite equilibrium electrode and the second electrode are electrically connected to generate an electrical potential indicative of the gas that is being sensed. In a particular embodiment of the present invention, the second electrode is a reference electrode that is exposed to a reference oxygen gas mixture so that the electrical potential is indicative of the oxygen in a gas stream.

Enhanced electrodes for solid state gas sensors

A potentiometric oxygen sensor is formed having a logarithmic response to a differential oxygen concentration while operating as a Nernstian-type sensor. Very thin films of mixed conducting oxide materials form electrode services while permitting diffusional oxygen access to the interface between the zirconia electrolyte and the electrode. Diffusion of oxygen through the mixed oxide is not rate-limiting. Metal electrodes are not used so that morphological changes in the electrode structure do not occur during extended operation at elevated temperatures.

Solid state oxygen sensor

Solid state oxygen sensors are provided with a yttria-doped zirconia as an electrolyte and use the electrochemical oxygen pumping of the zirconia electrolyte. A linear relationship between oxygen concentration and the voltage arising at a current plateau occurs when oxygen accessing the electrolyte is limited by a diffusion barrier. A diffusion barrier is formed herein with a mixed electronic and oxygen ion-conducting membrane of lanthanum-containing perovskite or zirconia-containing fluorite. A heater may be used to maintain an adequate oxygen diffusion coefficient in the mixed conducting layer.

Growing community of inventors

Los Alamos, NM, United States of America

Eric L Brosha