Honeywell International Inc.

Stefan-Dan Costea

Cornel P Cobianu

Bogdan-Catalin Serban

Viorel-Georgel Dumitru

Stefan Ioan Voicu

Ion Georgescu

Viorel Avramescu

Nicolae Varachiu

A piezoelectric strain sensor and method thereof for detecting strain, vibration, and/or pressure. The sensor incorporates a sequence of piezoelectric and semiconductor layers in a thin-film transistor structure. The thin-film transistor structure can be configured on a flexible substrate via a low-cost fabrication technique. The piezoelectric layer generates an electric charge resulting in a modulation of a transistor current, which is a measure of external strain. The sensor can be formed as a single gate field-effect piezoelectric sensor and a dual gate field-effect piezoelectric sensor. The semiconductor layer can be configured from a nanowire array resulting in a metal-piezoelectric-nanowire field effect transistor. The single and dual gate field-effect piezoelectric sensor offer increased sensitivity and device control due to the presence of the piezoelectric layer in the transistor structure and low cost manufacturability on large area flexible substrates.

Thin-film transistor based piezoelectric strain sensor and method

A method includes forming multiple trenches in a first wafer, forming a sensor structure on a first surface of a second wafer, and bonding the first wafer and the second wafer. The method also includes etching a second surface of the second wafer to form a sensor diaphragm in the second wafer. The method further includes removing a portion of the first wafer by cutting the first wafer in multiple areas of the first wafer associated with the trenches. A sensor includes a substrate and a surface acoustic wave (SAW) resonator on a first surface of the substrate. The sensor also includes a bonding pad electrically coupled to the SAW resonator and a notch formed in a second surface of the substrate. The sensor further includes a cover separated from the first surface of the substrate by a spacer. The SAW resonator is located between the cover and the substrate.

Method for sensor fabrication and related sensor and system

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

A method can be adapted for design and preparation of a matrix nanocomposite sensing film for hydrogen sulphide SAW/BAW detection at room temperature. A matrix nanocomposite can be synthesized by incorporating both single-wall and multi-wall thiolated carbon nanotubes into conductive organic polymers or ceramic nanocrystalline in a properly functionalized manner. A thin organic sensing film can be prepared based on the matrix nanocomposite. The matrix nanocomposite sensing film can be prepared on a surface of a SAW/BAW device by an additive process or a direct printing process. Finally, the sensing film can be consolidated by thermal annealing or laser annealing under ambient conditions in order to obtain the stable sensing film with higher sensitivity and electrical properties for a SAW/BAW based HS sensor.

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Bucharest, Romania

Stefan-Dan Costea