Honeywell International Inc.

Nicolae Varachiu

Cornel P Cobianu

Bogdan Catalin Serban

Stefan Ioan Voicu

Ion Georgescu

Bogdan-Catalin Serban

Mihai N Mihaila

Viorel-Georgel Dumitru

Cazimir Gabriel Bostan

Viorel Avramescu

Stefan-Dan Costea

Mircea Bercu

The design and deposition of a sensing layer for room temperature SAW/BAW chemical sensors utilizing macrocyclic compounds in accordance with supra-molecular chemistry principles. The gas to be sensed is attached to the organic sensing film thus changing its visco-elastic properties and creating a mass increase of the film deposited on the surface of SAW/BAW devices. A direct printing method can be used as an additive, mask-less procedure to deposit metallic interdigital transducers and electrodes required for SAW/BAW devices, along with the deposition of a guiding layer and the organic films only on the location required by the sensing SAW/BAW principle of the sensor. Different thermal treatment solutions can be used for the consolidation of the gelly organic films deposited by the direct printing methods.

Deposition of sensing layers for surface acoustic wave chemical sensors based on supra-molecular chemistry

The design and synthesis of a matrix nanocomposite containing amino carbon nanotubes used as a functionalized sensing layer for carbon dioxide detection by means acoustic wave sensing devices, e.g., SAW/BAW devices. These sensing materials contain a type of amino carbon nanotubes (single walled or multi-walled) and a polymer (or other compounds) which are sensitive to carbon dioxide in the acoustic wave sensing device based gas sensors. The sensitivity of the matrix consisting of the amino carbon nanotubes and a polymer (or other compounds) is ensured by the presence of amino groups which can react at room temperature with COin a reversible process to form carbamates.

Matrix nanocomposite containing aminocarbon nanotubes for carbon dioxide sensor detection

Methods can be adapted for design of a sensitive monolayer for detection of hydrogen sulphide at room temperature with SAW/BAW devices. The sensitive monolayer can be synthesized based on chemical compounds, which belongs to a class of thiacalix[n]arenas, mercapto halides, mercapto alcohols and chloromethylated thiacalix[n]arenas. The sensitive monolayer can be directly immobilized or anchored at the surface of a piezoelectric quartz substrate in a covalently bonded manner by means of direct printing process. The piezoelectric quartz substrate can be activated in basic medium or in acid medium before the immobilization of the sensitive monolayer in order to increase the population of OH groups. Thus, the synthesized sensitive monolayer exhibits a high site density, fast response and long-term stability for HS sensing.

Methods for use of a sensitive layer for hydrogen sulphide detection with SAW/BAW devices

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Bucharest, Romania

Nicolae Varachiu