Gas Research Institute

Atwood Industries, Inc.

Ceramatec, Inc.

Dura Global Technologies, Inc.

Atwood Systems and Controls

Walter Kidde Portable Equipment, Inc.

Yousheng Shen

Ashok V Joshi

Franco Consadori

Kevin Krist

Anil Vasudeo Virkar

Meilin Liu

John Howard Gordon

D George Field

Dale M Taylor

Michael J Boettcher

A highly accurate, long life, low cost gas sensor is disclosed, particularly useful for measuring carbon monoxide and other toxic gases in an environment. The gas sensor has a first, sensing electrode and a second, counting electrode. Positioned between the first and second electrodes is an ion conducting, solid electrolyte membrane. In response to the presence of a toxic gas introduced to the first electrode, an electric signal is produced between the first electrode and the second electrode. The electric signal changes in response to changes in the concentration of the toxic gas. Detection circuitry measures the electric signal to determine the concentration of the toxic gas. An electrically conductive, hydrophobic top membrane electrically connects the first electrode to the detection circuitry while preventing liquid water from contacting the first electrode. An electrically conductive, hydrophobic bottom membrane electrically connects the second electrode to the detection circuitry. The top and bottom membranes, though hydrophobic, are preferably also microporous so as to be gas permeable, including permeable to water vapor. Preferably the top and bottom membranes are ion insulating as well. Optionally the sensor is provided with a water reservoir to maintain constant relative humidity at the ion conducting electrolyte membrane. The sensor may also have a heating element. Internal and external self-diagnostic features to ensure that the sensor is functioning normally are disclosed, as well as self-calibration features, so as to ensure sensor accuracy.

Gas sensor with electrically conductive, hydrophobic membranes

Gas sensor with a diagnostic device

A highly accurate, long life, low cost gas sensor is disclosed, particularly useful for measuring oxygen in an environment. The gas sensor has a first, sensing electrode and a second, counting electrode. Dual electrolytes are electrically serially connected between the first and second electrodes. One of the electrolytes is an ion conducting solid electrolyte, the second is a liquid electrolyte. In response to an electric current an electrical characteristic is produced, and the electrical characteristic changes in response to changes in the concentration of a gas such as oxygen introduced at the first, sensing electrode. The solid electrolyte can be a perfluorinated polymer which advantageously controls the rate of the electrochemical reaction to give the sensor a long life without need for continuous recalibration. A dense liquid impermeable membrane may be positioned over the first electrode so that only gas reaches the first electrode and all gas that reaches the first electrode passes through the membrane. Advantageously, the solid electrolyte isolates the liquid electrolyte from the first, sensing electrode. The liquid electrolyte may comprise an acidic solution, a basic solution or a salt solution.

Gas sensor with dual electrolytes

A low cost room temperature electrochemical gas sensor with humidity compensation for sensing CO, alcohol vapors and other toxic analyte gases has a solid protonic conductive membrane with a low bulk ionic resistance. A sensing electrode and a counter electrode, optionally a counter electrode and a reference electrode, which are separated by the membrane, can be made of mixed protonic-electronic conductors, or can be made of a thin electrically conducting film such as platinum. A reservoir of water maintain the solid protonic conductive membrane at constant 100 percent relative humidity to compensate for ambient humidity changes. Embodiments of the inventive sensor also include an electrochemical analyte gas pump to transport the analyte gas away from the counter electrode side of the sensor. Analyte gas pumps for the inventive sensor include dual pumping electrodes situated on opposite sides of the membrane, and include a means for applying a DC power across the membrane to the sensing and counter electrodes. Another embodiment of the inventive sensor has first and second solid protonic conductive membranes, one of which has a sensing electrode and a counter electrode separated by the first membrane, and the other of which has dual pump electrodes situated on opposite sides of the second membrane.

Low cost room temperature electrochemical carbon monoxide and toxic gas

Enhancement of mechanical properties of ceramic membranes by introduction of a uniformly distributed high-temperature oxidation-resistant metal phase into the brittle ceramic phase to achieve mechanically strong ceramic/metal composites operable in an oxidation atmosphere and at elevated temperatures.

Enhancement of mechanical properties of ceramic membranes and solid

Composite ceramic mixed ionic and electronic conducting materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The mixed conducting materials have composite non-homogeneous microstructures of a separate predominantly oxygen ion conductive phase and a predominantly electronic conductive phase. Preferred predominantly oxygen ion conducting phases include bismuth, cerium and zirconium oxide based materials and predominantly electronic conducting phases include at least one metal electronic conductor material.

Mixed ionic-electronic conducting composites for oxygen separation and

A low cost room temperature electrochemical gas sensor for sensing CO and other toxic analyte gases has a solid protonic conductive membrane with a low bulk ionic resistance. A sensing electrode and a count counter electrode, which are separated by the membrane, can be made of mixed protonic-electronic conductors. Embodiments of the inventive sensor also include an electrochemical analyte gas pump to transport the analyte gas away from the counter electrode side of the sensor. Analyte gas pumps for the inventive sensor include dual pumping electrodes situated on opposite sides of the membrane, and include a means for applying a DC power across the membrane to the sensing and counter electrodes. Another embodiment of the inventive sensor has first and second solid protonic conductive membranes, one of which has a sensing electrode and a counter electrode separated by the first membrane, and the other of which has dual pumping electrodes situated on opposite sides of the second membrane.

Gas sensor based on protonic conductive membranes

A self-contained device which continuously dispenses a packaged fluid is disclosed. The device is particularly suited for applications where several months may lapse before performance is manually initiated, after which a consistent steady flow is required for an extended period until the packaged fluid is exhausted. The device is particularly suited for applications where ease of fabrication is important. The device utilizes an electrochemicalIy-generated gas, such as oxygen or nitrogen, to pressurize the packaged fluid to dispense it. Oxygen can be electrochemically released from a solid anode material of the general form AxOy as A ions migrate across a suitable ion-conducting electrolyte. Alternatively, nitrogen can be the pressurizing gas wherein it is electrochemically released from a solid, anode material of the general form A'.sub..alpha. N.sub..beta. where A' is a cation, as A' ions migrate across a suitable ion-conducting electrolyte. At the cathode, several possibilities may occur, either the migrated cations are reduced to their elemental state, or a solid material, R.sub.2, where R is a halogen, is reduced to R.sup.-, or solid material, R', where R' is a group VIB element other than oxygen is reduced to R'.sup.-2, or solid material CR.sub.x, is reduced to C+XR.sup.-. The released gas, oxygen or nitrogen, pressurizes a chamber resulting in fluid contained in a flexible bladder within the chamber to be forced through an outlet. Depending on the selection of anode and cathode materials, the device will be self driven or else will require a battery to provide a driving force.

Gas releasing electrochemical cell for fluid dispensing applications

A composite ceramic mixed oxygen ion and electronic conducting materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The mixed conducting materials have composite non-homogeneous microstructures of a separate predominantly oxygen ion conductive phase and a predominantly electronic conductive phase. Predominantly oxygen ion conducting phases include bismuth, cerium and thorium oxide based materials and predominantly electronic conducting phases include at least one metal, metal oxide of at least one metal, and at least one perovskite-type electronic conductor material.

Composite mixed ionic-electronic conductors for oxygen separation and

A self-contained device which continuously dispenses a packaged fluid is disclosed. The device is particularly suited for applications where several months may lapse before performance is manually initiated, after which a consistent steady flow is required for an extended period until the packaged fluid is exhausted. The device is particularly suited for applications where ease of fabrication is important. The device utilizes an electrochemically-generated gas, such as oxygen or nitrogen, to pressurize the packaged fluid to dispense it. Oxygen can be electrochemically released from a solid anode material of the general form AxOy as A ions migrate across a suitable ion-conducting electrolyte. Alternatively, nitrogen can be the pressurizing gas wherein it is electrochemically released from a solid, anode material of the general form A'.sub..alpha. N.sub..beta. where A' is a cation, as A' ions migrate across a suitable ion-conducting electrolyte. At the cathode, several possibilities may occur, either the migrated cations are reduced to their elemental state, or a solid material, R.sub.2, where R is a halogen, is reduced to R.sup.-, or solid material, R', where R' is a group VIB element other than oxygen is reduced to R'.sup.-2, or solid material CR.sub.x is reduced to C+XR.sup.-. The released gas, oxygen or nitrogen, pressurizes a chamber resulting in fluid contained in a flexible bladder within the chamber to be forced through an outlet. Depending on the selection of anode and cathode materials, the device will be self driven or else will require a battery to provide a driving force.

Mixed oxygen ion and electronic conducting bismuth oxide based ceramic materials having high ambipolar activity which can be fabricated into thin membranes for high efficiency oxygen separation from air at intermediate temperatures. The ceramic materials may be homogeneous microstructures in the form of solid solutions or compounds or may be composite non-homogeneous microstructures of a separate substantially continuous oxygen ion conductive phase and a substantially continuous electronic conductive phase.

Growing community of inventors

Salt Lake City, UT, United States of America

Yousheng Shen