# US 9,915,600 B2 · Devices, systems and methods for detecting particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,915,600 B2 - Document ID: US9915600B2 - Status: Granted - Kind: B2 - Application number: 15/048,199 - Filed: 2016-02-19 - Published: 2017-08-24 - Granted: 2018-03-13 - Earliest claimed: 2016-02-19 - Assignees: Research Triangle Institute - Applicants: Research Triangle Institute - Inventors: Howard Jerome Walls; Anthony Clint Clayton; Randall J. Newsome; Paul G. Hoertz - Web page: https://patentgrep.com/patent/US9915600B2 ## CPC - G01N 15/1436: {the optical arrangement forming an integrated apparatus with the sample container, e.g. a flow cell} - G01N 15/0205: by optical means - G01N 15/1459: {the analysis being performed on a sample stream} - G01N 21/53: within a flowing fluid, e.g. smoke - G01N 21/645: {Specially adapted constructive features of fluorimeters} - G01N 21/6486: {Measuring fluorescence of biological material, e.g. DNA, RNA, cells (G01N21/6428 takes precedence)} - G01N 2015/0046: {in gas, e.g. smoke} - G01N 2015/1486: {Counting the particles} - G01N 2015/1493: {Particle size} - G01N 2021/4721: {using a PSD} - G01N 2201/06113: Coherent sources; lasers - G01N 2201/062: LED's - 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) ## Abstract A particle detector includes a housing, a light source, and a photo-responsive material. The housing includes a sample inlet and a sample outlet, and encloses a detection cavity. The light source directs irradiating light to particles of a sample fluid flowing in the detection cavity. The photo-responsive material faces the detection cavity, and receives measurement light propagating from the particles in a plurality of measurement light paths angled relative to a longitudinal axis. The particle detector may be utilized to measure scattered light and/or light emitted due to autofluorescence. Fluids sampled may include aerosols, bio-aerosols, and liquids. ## Claims ### Claim 1 A particle detector, comprising: a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity along the longitudinal axis, and to the sample outlet; a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity; and a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis. ### Claim 2 (depends on 1) The particle detector of claim 1, wherein the photo-responsive material comprises a semiconductor having a band gap in a range selected from the group consisting of: about 2 eV or less; from about 0.67 eV to about 2 eV; about 1.7 eV or less; from about 0.67 eV to about 1.7 eV; from about 1.1 eV to about 1.7 eV; about 1.1 eV or less; and from about 0.67 eV to about 1.1 eV. ### Claim 3 (depends on 2) The particle detector of claim 2, wherein the semiconductor comprises crystalline silicon. ### Claim 4 (depends on 1) The particle detector of claim 1, wherein the detection cavity is generally polygonal and comprises a plurality of planar sides, and the photo-responsive material comprises one or more photo-responsive materials positioned at one or more of the respective sides. ### Claim 5 (depends on 1) The particle detector of claim 1, wherein the photo-responsive material comprises a plurality of photo-responsive materials, and the plurality of photo-responsive materials comprises at least two photo-responsive materials electrically coupled in series with each other or in parallel with each other. ### Claim 6 (depends on 1) The particle detector of claim 1, wherein the light source comprises a plurality of light sources. ### Claim 7 (depends on 6) The particle detector of claim 6, wherein at least one of the light sources is configured for emitting the irradiating light at an irradiating wavelength different from the other light sources. ### Claim 8 (depends on 6) The particle detector of claim 6, wherein: the plurality of light sources comprises a first light source and a second light source; the detection cavity comprises a first detection zone and a second detection zone downstream from the first detection zone; the first light source is configured for directing a first irradiating light through the first detection zone along the longitudinal axis; and the second light source is configured for directing a second irradiating light through the second detection zone. ### Claim 9 (depends on 8) The particle detector of claim 8, wherein the photo-responsive material comprises a first photo-responsive material configured for receiving first measurement light propagating from particles in the first detection zone, and a second photo-responsive material configured for receiving second measurement light propagating from the particles in the second detection zone. ### Claim 10 (depends on 8) The particle detector of claim 8, wherein the second light source is positioned downstream from the first light source. ### Claim 11 (depends on 8) The particle detector of claim 8, comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone. ### Claim 12 (depends on 8) The particle detector of claim 8, wherein the first detection zone and the second detection zone are positioned on the same longitudinal axis. ### Claim 13 (depends on 12) The particle detector of claim 12, comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone, wherein the second light source is positioned in the housing downstream from the mirror. ### Claim 14 (depends on 8) The particle detector of claim 8, wherein the longitudinal axis is a first longitudinal axis, the first detection zone is positioned on the first longitudinal axis, and the second detection zone is positioned on a second longitudinal axis oriented at an angle to the first longitudinal axis. ### Claim 15 (depends on 1) The particle detector of claim 1, wherein: the housing comprises an axial inlet section on the longitudinal axis between the sample inlet and the detection cavity, and an axial outlet section on the longitudinal axis between the detection cavity and the sample outlet, the axial inlet section and the axial outlet section having respective characteristic dimensions along a transverse direction orthogonal to the longitudinal axis; and the detection cavity has a characteristic dimension in a range from 0.1% to 200% greater than the characteristic dimension of the axial inlet section and the axial outlet section. ### Claim 16 (depends on 1) The particle detector of claim 1, comprising a plurality of mirrors in the detection cavity, wherein: the detection cavity has a dimension along a transverse axis orthogonal to the longitudinal axis; and the mirrors are configured for reflecting the irradiating light one or more times such that the irradiating light traverses the detection cavity two or more times along directions having a component along the transverse axis. ### Claim 17 (depends on 1) The particle detector of claim 1, comprising a beam chopper configured for chopping the irradiating light. ### Claim 18 (depends on 17) The particle detector of claim 17, wherein the beam chopper comprises a fluid moving device configured for moving the sample fluid through the detection cavity. ### Claim 19 A particle detector, comprising: a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet, wherein the detection cavity comprises a first detection zone and a second detection zone downstream from the first detection zone; a first light source configured for directing a first irradiating light to particles of the sample fluid flowing in the first detection zone; a second light source configured for directing a second irradiating light to particles of the sample fluid flowing in the second detection zone; and a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis. ### Claim 20 (depends on 19) The particle detector of claim 19, wherein the first light source is configured for emitting the irradiating light at an irradiating wavelength different from the second light source. ### Claim 21 (depends on 19) The particle detector of claim 19, wherein the photo-responsive material comprises a first photo-responsive material configured for receiving first measurement light propagating from particles in the first detection zone, and a second photo-responsive material configured for receiving second measurement light propagating from the particles in the second detection zone. ### Claim 22 (depends on 21) The particle detector of claim 21, wherein the photo-responsive material has a configuration selected from the group consisting of: at least one of the first photo-responsive material and the second photo-responsive material has a flat planar geometry; at least one of the first photo-responsive material and the second photo-responsive material has a flat planar geometry and comprises the semiconductor having a band gap 2 eV or less; at least one of the first photo-responsive material and the second photo-responsive material is flexible and surrounds at least a portion of the detection cavity; and two or more of the foregoing. ### Claim 23 (depends on 19) The particle detector of claim 19, wherein the second light source is positioned downstream from the first light source. ### Claim 24 (depends on 19) The particle detector of claim 19, comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone. ### Claim 25 (depends on 19) The particle detector of claim 19, wherein the first detection zone and the second detection zone are positioned on the same longitudinal axis. ### Claim 26 (depends on 25) The particle detector of claim 25, comprising a mirror configured for directing the first irradiating light out from the first detection zone such that the first irradiating light does not enter the second detection zone, wherein the second light source is positioned in the housing downstream from the mirror. ### Claim 27 (depends on 19) The particle detector of claim 19, wherein the first detection zone is positioned on a first longitudinal axis, and the second detection zone is positioned on a second longitudinal axis oriented at an angle to the first longitudinal axis. ### Claim 28 A particle detector, comprising: a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein: the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet along the longitudinal axis; the sample inlet comprises an axial inlet section on the longitudinal axis; the sample outlet comprises an axial outlet section on the longitudinal axis; the sample outlet comprises an axial outlet section on the longitudinal axis; the axial inlet section and the axial outlet section having respective maximum radial dimensions along a radial direction orthogonal to the longitudinal axis; and the detection cavity has a characteristic dimension in a range from 0.1% to 200% greater than the characteristic dimension of the axial inlet section and the axial outlet section; a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity; and a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis. ### Claim 29 (depends on 28) The particle detector of claim 28, wherein the photo-responsive material has a configuration selected from the group consisting of: the photo-responsive material has a flat planar geometry; the photo-responsive material has a flat planar geometry and comprises the semiconductor having a band gap 2 eV or less; and the photo-responsive material is flexible and surrounds at least a portion of the detection cavity. ### Claim 30 A particle detector, comprising: a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet along the longitudinal axis; a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity; a plurality of mirrors in the detection cavity, wherein: the detection cavity has a dimension along a transverse axis orthogonal to the longitudinal axis; and the mirrors are configured for reflecting the irradiating light one or more times such that the irradiating light traverses the detection cavity two or more times along directions having a component along the transverse axis; and a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis. ### Claim 31 (depends on 30) The particle detector of claim 30, wherein the photo-responsive material has a configuration selected from the group consisting of: the photo-responsive material has a flat planar geometry; the photo-responsive material has a flat planar geometry and comprises the semiconductor having a band gap 2 eV or less; and the photo-responsive material is flexible and surrounds at least a portion of the detection cavity. ### Claim 32 A particle detector, comprising: a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet; a light source configured for directing irradiating light along the longitudinal axis to particles of the sample fluid flowing in the detection cavity; a beam chopper configured for chopping the irradiating light; and a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis. ### Claim 33 (depends on 32) The particle detector of claim 32, wherein the photo-responsive material has a configuration selected from the group consisting of: the photo-responsive material has a flat planar geometry; the photo-responsive material has a flat planar geometry and comprises the semiconductor having a band gap 2 eV or less; and the photo-responsive material is flexible and surrounds at least a portion of the detection cavity. ### Claim 34 (depends on 32) The particle detector of claim 32, wherein the beam chopper comprises a fluid moving device configured for moving the sample fluid through the detection cavity.