Photo-acoustic gas sensor and method for the production and use thereof

• US 9,068,926 B2
• Filed: 10/07/2010
• Issued: 06/30/2015
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Schade, Wolfgang
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): ZHONG, XIN Y
• Application Number:
  US13/501,779
• Publication Number:
  US 20120260719A1
• Time in Patent Office: 1,727 Days
• Field of Search: 73/240.1, 73/240.2, 735/79, 356/432, 356/502
• US Class Current: 1/1
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2201/024 Modular construction

Abstract

A photo-acoustic gas sensor and methods for producing same, the gas sensor having a resonance body and a device for detecting a vibration of the resonance body, including a device for optically detecting the location of at least one partial surface of the resonance body, wherein the resonance body and the device for detecting a vibration are disposed on exactly one substrate, the resonance body is formed by at least one first recess of the substrate, and the substrate is a semiconductor material.

Claims

1. A photo-acoustic gas sensor, comprising a resonance body and an interferometer for identification of an oscillation of the resonance body by an optical detection of a location of at least one partial area of the resonance body, wherein the interferometer is arranged on exactly one substrate of a semiconductor material, and the resonance body is formed by at least one first cutout in the substrate which at least partly separates a first elongated element of the substrate from a portion of the substrate, wherein at least one of a device for generating light, a device for detecting light, a device for electronic signal processing, or a device for energy supply is integrated on the substrate of the semiconductor material.

2. The gas sensor according to claim 1, comprising further at least one resonator which at least partly delimits a volume intended for receiving molecules to be detected.

3. The gas sensor according to claim 2, wherein the resonator is connected to the substrate by means of a bonding method and/or is monolithically integrated in the substrate.

4. The gas sensor according to claim 1, comprising at least one first substrate, comprising the resonance body and the interferometer for identifying an oscillation of the resonance body, and at least one second substrate, on which at least one device for generating light and/or a device for detecting light and/or a device for electronic signal processing and/or a device for energy supply are/is integrated on the substrate, wherein the first substrate and the second substrate is connectable by means of electrical and/or optical contact elements.

5. The gas sensor according to claim 4, wherein the first substrate has a recess provided for receiving the second substrate.

6. The gas sensor according to claim 1, wherein the resonance body has at least the first elongated element and a second elongated element, wherein the first and second elongated elements are arranged approximately parallel to each other and wherein each of these elements is fixed to a connecting element at a base point and projects freely at their end opposite to the base point, wherein a second cutout is formed between the first elongated element and the second elongated element.

7. The gas sensor according to claim 1, wherein the interferometer comprises at least two optical waveguides which are guided parallel in a partial section, such that a crosstalk of the signals respectively guided in the optical waveguides is possible.

8. The gas sensor according to claim 1, wherein at least one first electronic component is integrated on the substrate by means of CMOS technology and/or a second electronic component is connected to the substrate by means of flip-chip bonding.

9. The gas sensor according to claim 1, wherein the device, for electronic signal processing comprises a device for the radio transmission of a data signal and/or an A/D converter and/or a signal amplifier and/or a discriminator and/or a receiving device for a data signal.

10. The gas sensor according to claim 1, wherein the device for energy supply comprises at least one photovoltaic cell or a monolithically integrated photovoltaic cell.

11. The gas sensor according to claim 1, comprising further at least one contact layer adapted to electrically connect at least one of:

at least two devices or at least two electronic components of a device.

12. The gas sensor according to claim 1, wherein at least one optical waveguide is integrated using silicon-on-insulator technology on and/or in the substrate.