Nano-proprietary, Inc.

Applied Nanotech Holdings, Inc.

Greg Monty

Kwok H Ng

Mohshi Yang

Zvi Yaniv

Yunjun Li

Prabhu Soundarrajan

Richard Finh

Kwok Ng

A hydrogen sensor and/or switch fabricated from an array of nanowires or a nanoparticle thick film composed of metal or metal alloys. The sensor and/or switch demonstrates a wide operating temperature range and shortened response time due to fabrication materials and methods. The nanowires or nanoparticle thick films demonstrate an increase in conductivity in the presence of hydrogen.

Method and apparatus for sensing hydrogen gas

The present invention provides for variable-range hydrogen sensors and methods for making same. Such variable-range hydrogen sensors comprise a series of fabricated Pd&#x2014;Ag (palladium-silver) nanowires&#x2014;each wire of the series having a different Ag to Pd ratio&#x2014;with nanobreakjunctions in them and wherein the nanowires have predefined dimensions and orientation. When the nanowires are exposed to H, their lattice swells when the Hconcentration reaches a threshold value (unique to that particular ratio of Pd to Ag). This causes the nanobreakjunctions to close leading to a 6-8 orders of magnitude decrease in the resistance along the length of the wire and providing a sensing mechanism for a range of hydrogen concentrations.

Formation of metal nanowires for use as variable-range hydrogen sensors

The present invention provides for novel hydrogen sensors and methods for making same. In some embodiments, such novel hydrogen sensors are continuous-range hydrogen sensors comprising Pd&#x2014;Ag nanoparticles arrayed as nanowires or two-dimensional shapes on a resistive surface. Such continuous-range hydrogen sensors are capable of measuring a wide range of hydrogen gas concentration over a wide temperature range. Unlike existing hydrogen sensors that experience a large change in resistance at a certain hydrogen concentration, the continuous-range hydrogen sensor of the present invention changes resistance continuously over a broad range of hydrogen concentration. This continuous change varies slowly with hydrogen concentration and is predictable such that the continuous-range hydrogen sensor can be used to measure hydrogen concentration continuously from a few ppm to 40,000 ppm level or higher over a broad range of temperatures (e.g., &#x2212;40&#xb0; C. to +150&#xb0; C.).

Continuous-range hydrogen sensors

The present invention provides for variable-range hydrogen sensors and methods for making same. Such variable-range hydrogen sensors comprise a series of fabricated Pd&#x2014;Ag (palladium-silver) nanowires&#x2014;each wire of the series having a different Ag to Pd ratio&#x2014;with nanobreakjunctions in them and wherein the nanowires have predefined dimensions and orientation. When the nanowires are exposed to H, their lattace swells when the Hconcentration reaches a threshold value (unique to that particular ratio of Pd to Ag). This causes the nanobreakjunctions to close leading to a 6&#x2013;8 orders of magnitude decrease in the resistance along the length of the wire and providing a sensing mechanism for a range of hydrogen concentrations.

The present invention provides for variable-range hydrogen sensors and methods for making same. Such variable-range hydrogen sensors comprise a series of fabricated Pd&#x2014;Ag (palladium-silver) nanowires&#x2014;each wire of the series having a different Ag to Pd ratio&#x2014;with nanobreakjunctions in them and wherein the nanowires have predefined dimensions and orientation. When the nanowires are exposed to H, their lattace swells when the Hconcentration reaches a threshold value (unique to that particular ratio of Pd to Ag). This causes the nanobreakjunctions to close leading to a 6-8 orders of magnitude decrease in the resistance along the length of the wire and providing a sensing mechanism for a range of hydrogen concentrations.

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Libertyville, IL, United States of America

Greg Monty