US Government As Represented by the Secretary of the Army

Other

Steven Clyde Hill

Richard Kounai Chang

Ronald Gene Pinnick

Yongle Pan

Horn-Bond Lin

Yong-Le Pan

Kristan Peter Gurton

Jean-Pierre Wolf

Kevin Bruce Aptowicz

Young-Le Pan

Embodiments of the present invention are directed to systems and methods for continuously sampling particles from air. In one embodiment, a system for continuously sampling particles from air may include: an airflow system configured to continuously draw air including airborne particles into the system; a photophoretic trap that uses photophoretic forces of a laser beam to trap one or more of the airborne particles from the drawn air; a measurement device configured to measure one or more properties of the trapped one or more airborne particles; and a controller configured to repeatedly trap, measure and release one or more airborne particles.

Systems and methods for individually trapping particles from air and measuring the optical spectra or other properties of individual trapped particles

Systems and methods for collecting particles are provided. A representative system includes an aerosol-into-liquid collector that stores a collection liquid. The aerosol-into-liquid collector also includes a container, a gas inlet, a gas outlet and a source of vacuum pressure such that, when the source of vacuum pressure provides vacuum pressure at the gas outlet, gas with particles entrained therein is drawn into the container through the gas inlet. A well holds a volume of the collection liquid such that at least some of the particles entrained in the gas collide with the collection liquid and adhere thereto. Gas drawn into the container impinges upon an exposed surface of the collection liquid in the well. Forces exerted by the gas do not tend to push the collection liquid out of the well or cause the collection liquid to break into multiple droplets.

Systems and methods for collecting particles from a large volume of gas into a small volume of liquid

Methods and systems for sorting particles entrained in a gaseous stream are disclosed. A representative system, among others, includes a particle scanner, a sorter, which is in pneumatic communication with the particle scanner, and a controller, which is in electrical communication with the particle scanner and sorter. The particle scanner is adapted to receive a gaseous stream and measure a characteristic of a particle entrained in the gaseous stream. The controller is adapted to classify the scanned particle according to the measured characteristic of the particle. The sorter includes an electrically controlled valve. Responsive to the particle being classified as belonging to a first category, the controller signals the valve to deflect the trajectory of the particle. A representative method, among others, for sorting particles entrained in a gaseous stream can be broadly summarized by the following steps: receiving particles in a gaseous stream; classifying a particle from the received stream of particles according to a property of the particle, wherein the particle is classified as belong to one category of a plurality of categories, and wherein the received particle has an initial trajectory; and responsive to the particle being classified as belonging to a first category of the plurality of categories, altering the trajectory of the particle.

Method and system for sorting particles sampled from air

An aerosol-into-liquid collector (ALC) for collecting gas-borne particles from a large volume of gas such as air into a small volume of liquid is described. The ALC uses a linear quadrupole to concentrate particles flowing in a gas and to help direct these concentrated particles toward a small volume of collection liquid so that these particles tend to combine with a small volume of collection liquid that can then be drawn from the ACL for further analysis. The particles in the gas are typically given a charge that is opposite to that of the charge imparted to the volume of collection liquid so that electrostatic forces help draw particles from the flowing gas into the small volume of liquid. The linear quadrupole focuses toward it axis particles that have the charge, mass and mobility to be stable in the linear quadrupole.

Aerosol into liquid collector for depositing particles from a large volume of gas into a small volume of liquid

Aerosol particle analyzer (APA) for measuring an analyte in airborne particle is described. Airborne particles are first given an electrical charge and then drawn in air past an oppositely charged volume of an analysis liquid that exposed to the air at a small hole in a container, such as a capillary, that holds that analysis liquid. Electrostatic forces enhance the rate that the airborne particles collide with the small exposed volume of the analysis liquid in the hole. If the particles that collide with the analysis liquid contain the analyte, an optical property of the analysis liquid, such as the fluorescence, varies according to the amount of the analyte in the particles. This optical property is measured and the amount of analyte in the particles is determined from the measured optical property.

Aerosol particle analyzer for measuring an analyte in airborne particles

Aerosol particle analyzer (APA) for measuring the amount of analyte in airborne particle is described. The APA uses an analysis liquid. In most embodiments, this analysis liquid is chosen so that when it is mixed with the particles, an optical property of the analysis liquid (AL) varies according to the amount of the analyte in the particles. Airborne particles are drawn into the instrument, and detected using optical methods such as light scattering or laser-induced fluorescence. When a particle of interest is detected, a charged droplet of the analysis liquid (CDAL) is ejected so that it collides with the detected particle and moves into a horizontally oriented linear quadrupole that is in an airtight container, except for small orifices to let the CDAL enter and exit. The CDAL is levitated in a high humidity environment so that it evaporates slowly, so that there is time for the reaction between the analyte, if any, and the CDAL can take place, and so that the optical property, typically fluorescence, can be measured. The amount of the analyte in the particle is determined from the measured fluorescence or other optical property. The particles collected into the CDAL can be sent on to other instruments for further analysis, especially to instruments that can analyze such small samples.

Aerosol particle analyzer for measuring the amount of analyte in airborne particles

Aerosol particle analyzer (APA) for measuring the amount of analyte in airborne particle is described. The APA uses an analysis liquid. When this analysis liquid is mixed with the particles, an optical property of the analysis liquid (CDAL) varies according to the amount of the analyte in the particles. A charged droplet of the analysis liquid is levitated. Airborne particles are drawn into the instrument and given a charge that is opposite that of the CDAL, and made to flow near the CDAL so that electrostatic forces greatly increase the probability that the CDAL and charged particles will combine. Then the CDAL is ejected into a horizontally oriented linear quadrupole that is in an airtight container, except for a small orifice to let the CDAL enter. The CDAL is levitated in a high humidity environment so that it evaporates slowly, so that there is time for the reaction between the analyte, if any, and the CDAL can take place, and so that the optical property, typically fluorescence, can be measured. The amount of the analyte in the particle is determined from the measured fluorescence or other optical property.

Characterizing individual airborne particles in real time according to their absorption of optical energy at one or more wavelengths. The instrument can measure the two-dimensional angular optical scattering (TAOS) and/or the one-dimensional angular optical scattering (ODAOS) at one or more wavelengths. When two wavelengths are used, one is chosen to be on an absorption peak, the other is off of the absorption peak (preferably in the absorption valley).

Method and instrumentation for determining absorption and morphology of individual airborne particles

A Fluorescence Particle Spectrometer (FPS) performs real-time measurement of the fluorescence spectra of aerosol particles in the size range 1-10 &#x3bc;m diameter. The FPS has a sufficiently high sample rate (estimated to be a few liters/min) to measure aerosol within buildings (from 1 up to 600 particle fluorescence spectra per minute) at practical rates. A virtual impactor first concentrates aerosol particles, which are then drawn under negative pressure through an aerodynamic focusing nozzle in the inlet of the instrument, through the sample region, providing further concentration. The rate of particle spectra measured by the FPS increases significantly when the particle inlet is within a few meters of some common sources of indoor biological particles.

Method and instrumentation for measuring fluorescence spectra of individual airborne particles sampled from ambient air

A method for fluorescence probing of particles flowing in a fluid includes defining a trigger volume in the fluid by intersecting a plurality of substantially orthogonally aimed trigger laser beams, each of a different wavelength, detecting light scattered from the vicinity of the trigger volume by a plurality of particle detectors each sensitive to a wavelength corresponding to the wavelength of a trigger laser beam, probing the particles with a pulsed laser triggered by the particle detectors, collecting fluorescence emitted from the particle in a detection volume and focusing it in a detection region, detecting the fluorescence focused in the detection region. The invention also includes devices for carrying out the foregoing method.

Aerosol fluorescence spectrum analyzer for rapid measurement of single airborne particles

The heel of the shoe, sneaker or other footwear is provided with a Velcro patch at the heel, with the Velcro patch having a cut-out window to accommodate an identification tag, label or health information card, with the label in the cut-out and the Velcro attached to the heel of the shoe being overlain with a releasably-attached flap having Velcro which mates with the shoe-mounted Velcro to form a fluid tight seal about the tag or indicia-carrying label, the heel mounting and the Velcro seal preventing the tag from coming loose from the shoe due to the interaction of the Velcro parts and due to the fact that the heel provides the least flexible area and the least wear receiving area for the shoe. The identity of the individual and other information on the tag is obtained from lifting the flap.

Growing community of inventors

Silver Spring, MD, United States of America

Steven Clyde Hill