Method and system for detecting an airborne trigger

• US 8,786,432 B2
• Filed: 11/30/2011
• Issued: 07/22/2014
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Miller, Robert
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): Akhter, Sharmin
• Application Number:
  US13/307,591
• Publication Number:
  US 20130135098A1
• Time in Patent Office: 965 Days
• Field of Search: 340/545.2, 340/545.4, 340/547, 340/561, 340/562, 340/566, 340577-579, 340628-630, 340/635, 340/657, 324/686
• US Class Current: 340/540
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 15/10 Investigating individual particles
• CPC Class Codes: G01N 2291/02408 Solids in gases, e.g. particle suspensions
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/44 Processing the detected response signal , e.g. electronic circuits specially adapted therefor digital signal processing per se G06F17/00
• CPC Class Codes: G01N 5/02 by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content absorption bulbs B01D53/00
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05D 19/02 characterised by the use of electric means
• CPC Class Codes: G08B 21/12 responsive to undesired emission of substances, e.g. pollution alarms

Abstract

An apparatus includes a cantilevered element including a coating material having an affinity for at least one compound. The apparatus further includes a first capacitive plate and a second capacitive plate that are each spaced from and capacitively coupled to the cantilevered element. The first capacitive plate is configured to induce a vibration in the cantilevered element at a frequency related to a mass of the cantilevered element. A frequency detector is coupled to the second capacitive plate to detect a change in vibrational frequency of the cantilevered element as a result of at least one particle of the at least one compound coupling to the coating material.

Claims

1. An apparatus comprising:

a cantilevered element including a coating material having an affinity for a compound;

a first capacitive plate spaced from and capacitively coupled to the cantilevered element, wherein the first capacitive plate is configured to induce a vibration in the cantilevered element at a frequency related to a mass of the cantilevered element;

a second capacitive plate spaced from and capacitively coupled to the cantilevered element; and

a frequency detector coupled to the second capacitive plate, the frequency detector adapted to detect a change in vibrational frequency of the cantilevered element as a result of particles of the compound coupling to the coating material, wherein the frequency detector is configured to generate an output associated with the vibrational frequency of the cantilevered element, and wherein the output is configured to be used by a processor to generate an alert when a threshold associated with the vibrational frequency is satisfied.

2. The apparatus of claim 1, wherein the cantilevered element is attached to a fixed device at one end.

3. The apparatus of claim 2, wherein:

the first capacitive plate is spaced from the fixed device; and

the second capacitive place plate is spaced from the fixed device.

4. The apparatus of claim 1, wherein the cantilevered element vibrates without contacting the first capacitive plate and without contacting the second capacitive plate.

5. The apparatus of claim 1, further comprising a frequency reference element coupled to the frequency detector.

6. The apparatus of claim 5, wherein the frequency detector is a frequency counter that detects the change in the vibrational frequency based on a reference frequency provided by the frequency reference element.

7. The apparatus of claim 1, wherein the second capacitive plate provides current at a frequency associated with the vibration of the cantilevered element.

8. The apparatus of claim 7, further comprising an amplifier to amplify the current.

9. An apparatus comprising:

a sensor array including a plurality of sensors, the plurality of sensors including a first sensor and a second sensor, wherein the first sensor includes;

a first cantilevered element including a first coating material having an affinity for a first compound;

a first capacitive plate spaced from and capacitively coupled to the first cantilevered element, wherein the first capacitive plate is configured to induce a vibration in the first cantilevered element at a first frequency related to a first mass of the first cantilevered element;

a second capacitive plate spaced from and capacitively coupled to the first cantilever; and

a first frequency detector coupled to the second capacitive plate, the first frequency detector to detect a first change in vibrational frequency of the first cantilevered element as a result of first particles of the first compound coupling to the first coating material, wherein the first frequency detector is configured to generate first sensor output associated with the vibrational frequency of the first cantilevered element;

wherein the sensor array generates sensor output including the first sensor output usable to generate an alert indicating presence of the first compound when the sensor output indicates a threshold associated with the first sensor is satisfied.

10. The apparatus of claim 9, wherein the second sensor includes:

a second cantilevered element including a second coating material having an affinity for a second compound;

a third capacitive plate spaced from and capacitively coupled to the second cantilevered element, wherein the third capacitive plate is configured to induce a vibration in the second cantilevered element at a second frequency related to a second mass of the second cantilevered element;

a fourth capacitive plate spaced from and capacitively coupled to the second cantilevered element; and

a second frequency detector coupled to the fourth capacitive plate, the second frequency detector to detect a second change in vibrational frequency of the second cantilevered element as a result of second particles of the second compound coupling to the second coating material.

11. The apparatus of claim 10, wherein the first coating material and the second coating material are the same.

12. The apparatus of claim 11, further comprising a diffusion barrier, wherein the diffusion barrier at least partially shields the first sensor, and wherein the first sensor detects a presence of the first particles at a different rate than the second sensor detects the presence of the second particles.

13. The apparatus of claim 10, wherein the first coating material and second coating material are different coating materials, wherein the first coating material has an affinity for a particular compound, and wherein the second coating material does not have affinity for the particular compound.

14. The apparatus of claim 10, further comprising a microcomputer interface to receive an output from each sensor of the plurality of sensors.

15. The apparatus of claim 14, wherein the microcomputer interface multiplexes outputs from each sensor of the plurality of sensors to generate a multiplexed output and wherein the sensor output includes the multiplexed output.

16. A method of communication data, the method comprising:

sending an association request from a sensor device to a manager device;

detecting a presence of a compound at the sensor device based on a sensor of the sensor device, wherein detecting the presence of the compound includes;

inducing a vibration in a cantilevered element via a first capacitive plate spaced from and capacitively coupled to the cantilevered element, wherein the vibration is related to a mass of the cantilevered element, and wherein the cantilevered element includes a coating material having an affinity for the compound;

providing an indication associated with a vibrational frequency of the cantilevered element via a second capacitive plate, wherein the second capacitive plate is spaced from and capacitively coupled to the cantilevered element; and

detecting a change in the vibrational frequency of the cantilevered element at a frequency detector based on the indication, wherein the change in the vibrational frequency results from particles of the compound coupling to the coating material, and wherein the frequency detector is coupled to the second capacitive plate; and

transmitting sensor data associated with the presence of the compound to the manager device in response to detecting the presence of the compound.

17. The method of claim 16, wherein the sensor data is included in an event report.

18. The method of claim 16, further comprising receiving an acknowledgment from the manager device.

19. The method of claim 16, further comprising transmitting a configuration event report including configuration information associated with the sensor device.

20. The method of claim 17, further comprising receiving a request to provide an attribute associated with the sensor device from the manager device.