Patents by Inventor Benjamin Y. H. Liu

Benjamin Y. H. Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11085861
    Abstract: An impactor, system and method for performing real-time measurements of particles in aerosol gases. The impactor comprises a plurality of cascading stages having impaction plates, mass-measurement mechanisms retained on the impaction plates, and a nozzle plate. A signal line associated with each of the plurality of cascading stages is configured to relay signals from the mass-measurement mechanism of the associated stage to a computer-based system configured to receive the transmitted signals from the signal lines, and to correlate changes in the resonant frequencies to particle concentrations in real time.
    Type: Grant
    Filed: March 3, 2015
    Date of Patent: August 10, 2021
    Assignee: MSP CORPORATION
    Inventors: Modi Chen, Lin Li, Virgil Alan Marple, Amir A. Naqwi, Francisco J. Romay, Daryl L. Roberts, Benjamin Y. H. Liu
  • Patent number: 10287679
    Abstract: An apparatus and method for generating a vapor with a compact vaporizer design and exposing the gas and liquid mixture for vaporization to a reduced maximum temperature. A gas and liquid droplet flow through a metal housing configured to heat the gas and liquid droplet mixture flow for vaporization includes directing the gas and liquid droplet mixture through an inlet of the metal housing and flowing the gas through a tortious flow path defined by a plurality of tubular flow passageways arranged around a central axis for vaporization. The flow path is directed through a heat exchanger including one more changes in direction of flow path before flowing into the further tortious flow path described above. Residual liquid droplets may be further vaporized by flowing through a second metal housing configured to heat the gas and liquid droplet mixture for vaporization and having a similar construction to the first metal housing and providing a second tortious flow path.
    Type: Grant
    Filed: October 23, 2017
    Date of Patent: May 14, 2019
    Assignee: MSP CORPORATION
    Inventors: Thuc M. Dinh, Yamin Ma, Benjamin Y. H. Liu
  • Patent number: 9895707
    Abstract: A method and apparatus for generating aerosol particles that are substantially uniform in size said apparatus includes a droplet generator comprised of a metal capillary for a liquid to flow through to form a liquid stream flowing into a gas stream. The metal capillary is vibrated by a piezoelectric ceramic at a substantially constant frequency to cause the liquid stream to breakup into droplets that are substantially uniform in size in the gas stream, the gas stream being maintained at a velocity in the range between approximately 10% to 100% of the speed of sound.
    Type: Grant
    Filed: April 29, 2015
    Date of Patent: February 20, 2018
    Assignee: MSP CORPORATION
    Inventors: Hongxu Duan, Francisco J. Romay, Amir A. Naqwi, Benjamin Y. H. Liu
  • Patent number: 9797593
    Abstract: An apparatus and method for generating a vapor with a compact vaporizer design and exposing the gas and liquid mixture for vaporization to a reduced maximum temperature. A gas and liquid droplet flow through a metal housing configured to heat the gas and liquid droplet mixture flow for vaporization includes directing the gas and liquid droplet mixture through an inlet of the metal housing and flowing the gas through a tortious flow path defined by a plurality of tubular flow passageways arranged around a central axis for vaporization. Residual liquid droplets may be further vaporized by flowing through a second metal housing configured to heat the gas and liquid droplet mixture for vaporization and having a similar construction to the first metal housing and providing a second tortious flow path.
    Type: Grant
    Filed: May 11, 2015
    Date of Patent: October 24, 2017
    Assignee: MSP Corporation
    Inventors: Thuc M. Dinh, Yamin Ma, Benjamin Y. H. Liu
  • Patent number: 9768005
    Abstract: A device and method are disclosed to apply ESI-based mass spectroscopy to submicrometer and nanometer scale aerosol particles. Unipolar ionization is utilized to charge the particles in order to collect them electrostatically on the tip of a tungsten rod. Subsequently, the species composing the collected particles are dissolved by making a liquid flow over the tungsten rod. This liquid with dissolved aerosol contents is formed into highly charged droplets, which release unfragmented ions for mass spectroscopy, such as time-of-flight mass spectroscopy. The device is configured to operate in a switching mode, wherein aerosol deposition occurs while solvent delivery is turned off and vice versa.
    Type: Grant
    Filed: April 21, 2016
    Date of Patent: September 19, 2017
    Assignees: MSP Corporation, Regents of the University of Minnesota
    Inventors: Siqin He, Chris Hogan, Lin Li, Benjamin Y. H. Liu, Amir Naqwi, Francisco Romay
  • Patent number: 9764333
    Abstract: A method and apparatus are disclosed for exposing particles in a gas in order to cause the charge on the particles to change, the apparatus comprising a chamber having a conductive wall with a gas inlet and a gas outlet. An electrode with an exposed tip is in the chamber, the electrode being held at a different potential from the ground potential. The electrode is connected to a source of voltage sufficient to cause a corona discharge to occur forming ions in the chamber, and creating a region with a high electric field intensity and another region in which the electric field intensity is lower. The inlet and outlet define a gas flow path from the inlet to the outlet such that the gas flow path passes mainly through the region with the lower electric field intensity.
    Type: Grant
    Filed: October 12, 2010
    Date of Patent: September 19, 2017
    Assignee: MSP CORPORATION
    Inventors: William Dick, Francisco J. Romay, Benjamin Y. H. Liu
  • Patent number: 9541488
    Abstract: An apparatus and method for sampling and measuring air born particulate matter includes an inlet for the particulate containing gas to enter. A mechanism then removes coarse particles larger than a selected size while permitting filtered particles of less than the selected size to pass through. A chamber containing a quartz crystal sensor permits the filtered particles that have passed through to deposit to create an output signal in response to the deposited particle mass.
    Type: Grant
    Filed: September 19, 2013
    Date of Patent: January 10, 2017
    Assignee: MSP CORPORATION
    Inventors: Benjamin Y. H. Liu, Virgil A. Marple, Francisco Romay, Lin Li
  • Patent number: 8986784
    Abstract: A method for forming a droplet aerosol for vaporization and subsequent thin film deposition on a substrate. The method includes drawing a gas from a compressed gas source and drawing a liquid from a liquid source. The liquid and gas are conjoined in either a coaxial flow relationship or a radial flow relationship or an angular relationship between radial and coaxial flow wherein the gas engages the liquid to form droplets suitable for vaporization and subsequent thin film deposition on a substrate.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: March 24, 2015
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, Yamin Ma
  • Patent number: 8945281
    Abstract: The present disclosure describes an apparatus and a method for generating IPA vapor for condensation on a substrate in order to provide a vapor that is substantially free of particulate and molecular contaminants. The apparatus includes an inlet for liquid to enter, and a plurality of heated sloped surfaces to create thin sheets of flowing liquid on the surfaces from which the liquid can vaporize to form vapor. The liquid flows from one surface to another, vaporizing the liquid.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: February 3, 2015
    Assignee: MSP Corporation
    Inventors: Thuc M. Dinh, Yamin Ma, Benjamin Y. H. Liu
  • Patent number: 8783652
    Abstract: An apparatus for controlling liquid flow wherein the apparatus comprises an orifice and an adjacent flexible diaphragm separated from each other by a gap through which a liquid flows. The diaphragm is sufficiently flexible to vary the gap thereby controlling the rate of liquid flowing through the orifice or to provide a positive liquid shutoff of liquid flowing through the orifice. A method for controlling liquid flow through the apparatus comprises flexing said diaphragm to vary a size of the gap to control the rate of liquid flowing through the orifice or to provide a positive liquid shutoff of liquid from flowing through the orifice.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: July 22, 2014
    Assignee: MPS Corporation
    Inventors: Thuc M. Dinh, Benjamin Y. H. Liu, Yamin Ma
  • Patent number: 8728240
    Abstract: Methods and apparatus for recovery of precursor vapor from a gas and precursor vapor mixture used in a deposition process. The gas and precursor vapor mixture is passed through a multitude of heat transfer surfaces in a heat conducting housing causing the precursor vapor to condense. The precursor vapor in liquid form is then collected after condensation.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: May 20, 2014
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, Yamin Ma
  • Patent number: 8711338
    Abstract: The present disclosure describes a method and apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: April 29, 2014
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, William D. Dick, Aaron M. Collins, Francisco J. Romay
  • Publication number: 20140083167
    Abstract: An apparatus and method for sampling and measuring air born particulate matter includes an inlet for the particulate containing gas to enter. A mechanism then removes coarse particles larger than a selected size while permitting filtered particles of less than the selected size to pass through. A chamber containing a quartz crystal sensor permits the filtered particles that have passed through to deposit to create an output signal in response to the deposited particle mass.
    Type: Application
    Filed: September 19, 2013
    Publication date: March 27, 2014
    Applicant: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Virgil A. Marple, Francisco Romay, Lin Li
  • Patent number: 8603580
    Abstract: A method for vaporizing a liquid for subsequent thin film deposition on a substrate. The method comprises vaporizing a liquid which is disposed within a tubular porous metal body. The porous metal body comprises a first surface defining a first carrier gas flow path and a second surface defining a second carrier gas flow path in a substantially opposite direct to the first carrier flow path. Vapor is generated from the liquid and added to a carrier gas that passes sequentially in direct contact along the first and second surfaces of the porous metal body to form a gas/vapor mixture with the carrier gas first flowing along the first surface and then along the second surface thereby providing a gas/vapor mixture for thin film deposition.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: December 10, 2013
    Assignee: MSP Corporation
    Inventor: Benjamin Y. H. Liu
  • Patent number: 8603247
    Abstract: The present disclosure describes an apparatus for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: December 10, 2013
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, William D. Dick, Aaron M. Collins, Francisco J. Romay
  • Patent number: 8554064
    Abstract: The present disclosure relates to an apparatus and a method for vaporizing a liquid to form vapor preferably in a gas stream. The apparatus includes a composite metal structure, the structure comprising a plurality of passageways for providing heat to vaporize the liquid in the gas stream to form a gas/vapor mixture. A non-corrosive interface lies between the metal structure and the gas/vapor mixture, the interface being chemically inert to the gas/vapor mixture and the structure permitting heat to be conducted rapidly therethrough to vaporize the liquid. The apparatus further includes an inlet for the gas and an inlet for the liquid to be vaporized to flow into the plurality of passageways and an exit through which the gas/vapor mixture exits the apparatus.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: October 8, 2013
    Assignee: MSP Corporation
    Inventors: Thuc Dinh, Yamin Ma, Benjamin Y. H. Liu
  • Patent number: 8529985
    Abstract: A method for atomizing a precursor liquid for vapor generation and thin film deposition on a substrate. The precursor liquid is atomized by a carrier gas to form a droplet aerosol composed of small precursor liquid droplets suspended in the carrier gas. The droplet aerosol is then heated to form vapor, producing a gas/vapor mixture that can be introduced into a deposition chamber to form thin films on a substrate. The liquid is introduced into the atomizing apparatus in such a manner as to avoid excessive heating that can occur or lead to the formation of undesirable by-products due to material degradation as result of thermal decomposition. The method is particularly suited for vaporizing high molecular weight substances with a low vapor pressure that requires a high vaporization temperature for the liquid to vaporize. The method can also be used to vaporize solid precursors dissolved in a solvent for vaporization.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: September 10, 2013
    Assignee: MSP Corporation
    Inventor: Benjamin Y. H. Liu
  • Patent number: 8511583
    Abstract: The present disclosure relates to an apparatus and a method for forming a droplet aerosol for vaporization and subsequent thin film deposition on a substrate. The apparatus includes a mechanism to control the rate of liquid flow through the apparatus, the mechanism including a piezoelectric actuator to adjust the rate of liquid flow and an atomizing mechanism drawing gas from a compressed gas source such that when the gas source conjoins with the liquid, the liquid is atomized to form droplets suspended in the gas thereby forming a droplet aerosol suitable for subsequent thin film deposition on a substrate. The method includes drawing a gas from a compressed gas source and drawing a liquid from a liquid source. The liquid and gas are conjoined in either a coaxial flow relationship or a radial flow relationship or an angular relationship between radial and coaxial flow wherein the gas engages the liquid to form droplets suitable for vaporization and subsequent thin film deposition on a substrate.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: August 20, 2013
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, Yamin Ma
  • Patent number: 8465791
    Abstract: A method for detecting particles in a gas by saturating the gas with vapor and causing the gas to flow through a chamber with walls that are at a temperature different than the temperature of the entering gas creating a gas turbulence within the chamber resulting in the gas becoming super-saturated with vapor and causing said super-saturated vapor to condense on said particles and form droplets, which are then detected and counted by an optical light-scattering detector.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: June 18, 2013
    Assignee: MSP Corporation
    Inventors: Benjamin Y. H. Liu, Thuc M. Dinh, William D. Dick, Aaron M. Collins, Francisco J. Romay
  • Patent number: 8393599
    Abstract: An apparatus for atomizing a precursor liquid for vapor generation and thin film deposition on a substrate. The precursor liquid is atomized by a carrier gas to form a droplet aerosol composed of small precursor liquid droplets suspended in the carrier gas. The droplet aerosol is then heated to form vapor, producing a gas/vapor mixture that can be introduced into a deposition chamber to form thin films on a substrate. The liquid is introduced into the atomizing apparatus in such a manner as to avoid excessive heating that can occur or lead to the formation of undesirable by-products due to material degradation as result of thermal decomposition. The apparatus is particularly suited for vaporizing high molecular weight substances with a low vapor pressure that requires a high vaporization temperature for the liquid to vaporize. The apparatus can also be used to vaporize solid precursors dissolved in a solvent for vaporization.
    Type: Grant
    Filed: February 2, 2012
    Date of Patent: March 12, 2013
    Assignee: MSP Corporation
    Inventor: Benjamin Y. H. Liu