Patents by Inventor Jeffrey A. Hopwood
Jeffrey A. Hopwood 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).
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Patent number: 9647414Abstract: A laser and methods for providing a continuous wave output beam. The laser and method includes positioning a micro-plasma chip capable of creating micro-plasmas within a resonant cavity. A gas is input into the resonant cavity and flows around the micro-plasma chip. Micro-plasmas ignite and excite the gas to create metastables. The metastables are further excited by an optical pump having an energy sufficient to cause the metastables to lase.Type: GrantFiled: January 30, 2014Date of Patent: May 9, 2017Assignee: Physical Sciences, Inc.Inventors: W. Terry Rawlins, Steven J. Davis, Kristin Galbally-Kinney, Jeffrey Hopwood, Alan Hoskinson
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Patent number: 9460884Abstract: A microplasma generator includes first and second conductive resonators disposed on a first surface of a dielectric substrate. The first and second conductive resonators are arranged in line with one another with a gap defined between a first end of each resonator. A ground plane is disposed on a second surface of the dielectric substrate and a second end of each of the first and second resonators is coupled to the ground plane. A power input connector is coupled to the first resonator at a first predetermined distance from the second end chosen as a function of the impedance of the first conductive resonator. A microplasma generating array includes a number of resonators in a dielectric material substrate with one end of each resonator coupled to ground. A micro-plasma is generated at the non-grounded end of each resonator. The substrate includes a ground electrode and the microplasmas are generated between the non-grounded end of the resonator and the ground electrode.Type: GrantFiled: July 26, 2012Date of Patent: October 4, 2016Assignee: Trustees of Tufts CollegeInventors: Jeffrey A. Hopwood, Chen Wu, Alan R. Hoskinson, Sameer Sonkusale
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Patent number: 9006972Abstract: A low-temperature, atmospheric-pressure microplasma generator comprises at least one strip of metal on a dielectric substrate. A first end of the strip is connected to a ground plane and the second end of the strip is adjacent to a grounded electrode, with a gap being defined between the second end of the strip and the grounded electrode. High frequency power is supplied to the strip. The frequency is selected so that the length of the strip is an odd integer multiple of ¼ of the wavelength traveling on the strip. A microplasma forms in the gap between the second end of the strip and the grounded electrode due to electric fields in that region. A microplasma generator array comprises a plurality of strongly-coupled resonant strips in close proximity to one another. At least one of the strips has an input for high-frequency electrical power. The remaining strips resonate due to coupling from the at least one powered strip. The array can provide a continuous line or ring of plasma.Type: GrantFiled: April 27, 2010Date of Patent: April 14, 2015Assignee: Trustees of Tufts CollegeInventor: Jeffrey A. Hopwood
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Publication number: 20140159571Abstract: A microplasma generator includes first and second conductive resonators disposed on a first surface of a dielectric substrate. The first and second conductive resonators are arranged in line with one another with a gap defined between a first end of each resonator. A ground plane is disposed on a second surface of the dielectric substrate and a second end of each of the first and second resonators is coupled to the ground plane. A power input connector is coupled to the first resonator at a first predetermined distance from the second end chosen as a function of the impedance of the first conductive resonator. A microplasma generating array includes a number of resonators in a dielectric material substrate with one end of each resonator coupled to ground. A micro-plasma is generated at the non-grounded end of each resonator. The substrate includes a ground electrode and the microplasmas are generated between the non-grounded end of the resonator and the ground electrode.Type: ApplicationFiled: July 26, 2012Publication date: June 12, 2014Applicant: Trustees of Tufts CollegeInventors: Jeffrey A. Hopwood, Chen Wu, Alan R. Hoskinson, Sameer Sonkusale
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Publication number: 20120045863Abstract: A low-temperature, atmospheric-pressure microplasma generator comprises at least one strip of metal on a dielectric substrate. A first end of the strip is connected to a ground plane and the second end of the strip is adjacent to a grounded electrode, with a gap being defined between the second end of the strip and the grounded electrode. High frequency power is supplied to the strip. The frequency is selected so that the length of the strip is an odd integer multiple of ¼ of the wavelength traveling on the strip. A microplasma forms in the gap between the second end of the strip and the grounded electrode due to electric fields in that region. A microplasma generator array comprises a plurality of strongly-coupled resonant strips in close proximity to one another. At least one of the strips has an input for high-frequency electrical power. The remaining strips resonate due to coupling from the at least one powered strip. The array can provide a continuous line or ring of plasma.Type: ApplicationFiled: April 27, 2010Publication date: February 23, 2012Inventor: Jeffrey A. Hopwood
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Patent number: 7728253Abstract: A system and method employing a microplasma to electrically charge nano- or micro-particles in a gas phase and, subsequently, trap the charged particles within the microplasma using the microplasma's built-in electric fields are disclosed. Confinement of the particles allows their density to be increased over time such that very low concentrations of particles can be detected, e.g., by methods such as laser scattering and/or detection of the plasma-induced charge on the particles. Preferably, charge detection methods are employed when nano-particles are to be trapped and detected.Type: GrantFiled: June 29, 2006Date of Patent: June 1, 2010Assignee: Northeastern UniversityInventor: Jeffrey A. Hopwood
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Publication number: 20100072391Abstract: A system and method employing a microplasma to electrically charge nano- or micro-particles in a gas phase and, subsequently, trap the charged particles within the microplasma using the microplasma's built-in electric fields are disclosed. Confinement of the particles allows their density to be increased over time such that very low concentrations of particles can be detected, e.g., by methods such as laser scattering and/or detection of the plasma-induced charge on the particles. Preferably, charge detection methods are employed when nano-particles are to be trapped and detected.Type: ApplicationFiled: June 29, 2006Publication date: March 25, 2010Inventor: Jeffrey A. Hopwood
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Patent number: 7256669Abstract: Processes for preparing contacts on microswitches have been invented. The first is a wet process, involving the use of one or more acids, bases and peroxides, in some formulations diluted in water, to flush the contacts. The second process involves exposing the contacts to plasmas of various gases, including (1) oxygen, (2) a mixture of carbon tetrafluoride and oxygen, or (3) argon.Type: GrantFiled: April 27, 2001Date of Patent: August 14, 2007Assignee: Northeastern UniversityInventors: Richard H. Morrison, Jr., Nicol E. McGruer, Jeffrey A. Hopwood
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Publication number: 20070065576Abstract: A technique for atomic layer deposition is disclosed. In one particular exemplary embodiment, the technique may be realized by an apparatus for atomic layer deposition. The apparatus may comprise a process chamber having a substrate platform to hold at least one substrate. The apparatus may also comprise a supply of a precursor substance, wherein the precursor substance comprises atoms of at least one first species and atoms of at least one second species, and wherein the supply provides the precursor substance to saturate a surface of the at least one substrate. The apparatus may further comprise a plasma source of metastable atoms of at least one third species, wherein the metabstable atoms are capable of desorbing the atoms of the at least one second species from the saturated surface of the at least one substrate to form one or more atomic layers of the at least one first species.Type: ApplicationFiled: September 9, 2005Publication date: March 22, 2007Inventors: Vikram Singh, Harold Persing, Edmund Winder, Jeffrey Hopwood, Anthony Renau
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Patent number: 6917165Abstract: A low power plasma generator is provided which can be fabricated in micro-miniature size and which is capable of efficient portable operation. The plasma generator comprises a microwave stripline high Q resonant ring, which may be circular or non-circular, disposed on a dielectric substrate and having a discharge gap in the plane of the substrate. The resonant ring is one-half wavelength in circumference at the operating frequency and is matched to the impedance of the microwave power supply. The voltages at the resonator ends at the gap are 180° out of phase and create an intense electric field in the gap, and a resultant discharge across the gap. The discharge is non-thermal and operates near room temperature and has an intense optical emission. The generator is well suited for low power portable and other applications and can be readily fabricated by known microcircuit techniques. Alternatively, the gap of the resonant ring can extend through the substrate and in which the discharge is formed.Type: GrantFiled: December 22, 2003Date of Patent: July 12, 2005Assignee: Northeastern UniversityInventors: Jeffrey A. Hopwood, Felipe Iza
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Publication number: 20040164682Abstract: A low power plasma generator is provided which can be fabricated in micro-miniature size and which is capable of efficient portable operation. The plasma generator comprises a microwave stripline high Q resonant ring, which may be circular or non-circular, disposed on a dielectric substrate and having a discharge gap in the plane of the substrate. The resonant ring is one-half wavelength in circumference at the operating frequency and is matched to the impedance of the microwave power supply. The voltages at the resonator ends at the gap are 180° out of phase and create an intense electric field in the gap, and a resultant discharge across the gap. The discharge is non-thermal and operates near room temperature and has an intense optical emission. The generator is well suited for low power portable and other applications and can be readily fabricated by known microcircuit techniques. Alternatively, the gap of the resonant ring can extend through the substrate and in which the discharge is formed.Type: ApplicationFiled: December 22, 2003Publication date: August 26, 2004Inventors: Jeffrey A. Hopwood, Felipe Iza
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Publication number: 20020088112Abstract: Processes for preparing contacts on microswitches have been invented. The first is a wet process, involving the use of one or more acids, bases and peroxides, in some formulations diluted in water, to flush the contacts. The second process involves exposing the contacts to plasmas of various gases, including (1) oxygen, (2) a mixture of carbon tetrafluoride and oxygen, or (3) argon.Type: ApplicationFiled: April 27, 2001Publication date: July 11, 2002Inventors: Richard H. Morrison, Nicol E. McGruer, Jeffrey A. Hopwood
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Patent number: 6077572Abstract: A method of creating a diamond-like carbon film on a substrate, including the steps of exposing the substrate to a hydrocarbon gas environment and generating plasma in the environment of an electron density greater than approximately 5.times.10.sup.10 per cm.sup.3 and a sheath thickness less than about 2 mm under conditions of high ion flux and controlled, low energy ion bombardment.Type: GrantFiled: June 18, 1997Date of Patent: June 20, 2000Assignee: Northeastern UniversityInventors: Jeffrey A. Hopwood, David L. Pappas
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Patent number: 5942855Abstract: A monolithic inductively coupled plasma generator includes a first substrate having an electrical circuit disposed thereon which includes a substantially planar inductive coil, a capacitor electrically coupled in series with the coil, and a drive circuit electrically coupled to the coil for driving the circuit at resonance. The plasma generator further includes a plasma chamber proximate the coil in which a gas is excited.Type: GrantFiled: August 28, 1996Date of Patent: August 24, 1999Assignee: Northeastern UniversityInventor: Jeffrey A. Hopwood
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Patent number: 5622635Abstract: A method of gas plasma treating a workpiece in a process chamber having RF coil outside the chamber, a flat dielectric window, and a electrically conducting shield, adapted to be located between the RF coil and the dielectric window. The shield comprises a planar body section having a periphery, central opening, and outer gaps forming a substantially continuous opening about the periphery. A uniform magnetic field, inductively coupled with the plasma, is formed by routing the flux lines of the magnetic field through the central opening and outer gaps of the shield. Contamination from sputtering is substantially eliminated by reducing the capacitive electric fields generated by the coil that interfere with the inductive coupling between the coil and the gas plasma.Type: GrantFiled: April 5, 1995Date of Patent: April 22, 1997Assignee: International Business Machines CorporationInventors: Jerome J. Cuomo, C. Richard Guarnieri, Jeffrey A. Hopwood
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Patent number: 5433812Abstract: A shield for shunting capacitive electric fields generated by an RF coil away from a gas plasma process chamber's dielectric window and toward ground. The shield comprise an electrically conducting, substantially planar body section having a periphery and adapted to be located between the RF coil and the dielectric window during plasma treating of a workpiece. A central opening in the body section and gaps about the periphery permit RF magnetic fields to inductively couple with the plasma and return around the coil, respectively. The shield substantially reduces interference by capacitive electric fields generated by the coil with inductive coupling between the coil and the gas plasma, thus substantially eliminating contamination from sputtering of the dielectric window by the capacitive electric fields.Type: GrantFiled: January 19, 1993Date of Patent: July 18, 1995Assignee: International Business Machines CorporationInventors: Jerome J. Cuomo, C. Richard Guarnieri, Jeffrey A. Hopwood
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Patent number: 5280154Abstract: A plasma processing apparatus comprising: a chamber for supporting a workpiece; an inlet for introducing a gas into the chamber; a coil of conductive material having a generally flattened configuration whereby to provide a at least one generally planar surface defined by parallel conductors disposed on the chamber; and apparatus for applying radio frequency energy to the coil.Type: GrantFiled: January 30, 1992Date of Patent: January 18, 1994Assignee: International Business Machines CorporationInventors: Jerome J. Cuomo, Charles R. Guarnieri, Jeffrey A. Hopwood, Stanley J. Whitehair
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Patent number: 5081398Abstract: An improved apparatus for generating a uniform electron cyclotron resonance (ECR) region in a plasma region (16) of a chamber (15) is described. The apparatus uses higher modes of electrical field cusps (16b) which are essentially perpendicular to the magnetic field cusps (16a) in a controlled manner to produce the ECR. The modes are optimal in the ECR region.Type: GrantFiled: October 20, 1989Date of Patent: January 14, 1992Assignee: Board of Trustees operating Michigan State UniversityInventors: Jes Asmussen, Jeffrey A. Hopwood