# US 8,786,432 B2 · Method and system for detecting an airborne trigger > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,432 B2 - Document ID: US8786432B2 - Status: Granted - Kind: B2 - Application number: 13/307,591 - Filed: 2011-11-30 - Published: 2013-05-30 - Granted: 2014-07-22 - Earliest claimed: 2011-11-30 - Assignees: AT&T Intellectual Property I, L.P. - Applicants: Robert Miller - Inventors: Robert Miller - Web page: https://patentgrep.com/patent/US8786432B2 ## CPC - G01N 15/10: Investigating individual particles - 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)} - G01N 15/06: Investigating concentration of particle suspensions (by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10) - 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)} - G01N 29/44: Processing the detected response signal {, e.g. electronic circuits specially adapted therefor (digital signal processing per se G06F17/00)} - G05B 15/02: electric - G05D 19/02: characterised by the use of electric means - G08B 21/12: responsive to undesired emission of substances, e.g. pollution alarms - G01N 2291/02408: Solids in gases, e.g. particle suspensions - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## 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 ### Claim 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. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the cantilevered element is attached to a fixed device at one end. ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the cantilevered element vibrates without contacting the first capacitive plate and without contacting the second capacitive plate. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a frequency reference element coupled to the frequency detector. ### Claim 6 (depends on 5) 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. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the second capacitive plate provides current at a frequency associated with the vibration of the cantilevered element. ### Claim 8 (depends on 7) The apparatus of claim 7, further comprising an amplifier to amplify the current. ### Claim 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. ### Claim 10 (depends on 9) 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. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the first coating material and the second coating material are the same. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 10) 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. ### Claim 14 (depends on 10) The apparatus of claim 10, further comprising a microcomputer interface to receive an output from each sensor of the plurality of sensors. ### Claim 15 (depends on 14) 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. ### Claim 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. ### Claim 17 (depends on 16) The method of claim 16, wherein the sensor data is included in an event report. ### Claim 18 (depends on 16) The method of claim 16, further comprising receiving an acknowledgment from the manager device. ### Claim 19 (depends on 16) The method of claim 16, further comprising transmitting a configuration event report including configuration information associated with the sensor device. ### Claim 20 (depends on 17) The method of claim 17, further comprising receiving a request to provide an attribute associated with the sensor device from the manager device.