Georgia Tech Research Corporation

Thomas Michael Orlando

Robert Craig Murphy

Phillip N First

Robert M Barkley

Yanfeng Chen

Zhigang Jiang

Joshua Milbourne Symonds

Elliot Christian Frey

Denis Aleksandrovich Sokolov

M Cameron Sullards

Kristin Rene Shepperd

Joseph A Hankin

A radiation detector () includes an insulating substrate (), which includes a material that undergoes a change in an electrical property when subjected to ionizing radiation. A conductive film () is disposed in relation to a surface of the substrate. The conductive film () has a resistance that is a function of a state of the electrical property. A resistance measuring device measures resistance across the conductive film (). The resistance measured by the resistance measuring device indicates an amount of ionizing radiation to which the substrate () has been subjected. In a method of determining exposure to a type of radiation, a boron nitride substrate is exposed to a radiation environment. A resistance is measured across a conductive film disposed in relation to the boron nitride substrate. Radiation exposure is calculated as a function of the resistance.

Electrical resistance device for radiation detection

Graphene production using a continuous or pulsed laser beam focused on a substrate of graphite oxide in a significantly inert environment is disclosed. Laser-induced graphene features are characterized by a 2D-band in the Raman spectra. When the photons of the laser at a various frequencies and power levels beam impinge a graphite oxide foil for various amounts of time, a strip, divet, trench, or hole, having graphene at the bottom or sides is produced. The concentration of the graphite oxide and the laser beam may be adjusted so that the depth of the trench created is a certain depth less than the thickness of the foil. Additionally, in some embodiments, the evaporation of the water during the Hummers method is adjusted so that there remains interlaminar water in the graphite oxide foil. The presently disclosed subject matter may also be used in patterning using rastering or substrate motion.

Production of graphene sheets and features via laser processing of graphite oxide/ graphene oxide

A method and system for desorbing and ionizing molecules from a sample for mass spectrometry using a microplasma device is disclosed. The system and method relies upon a microplasma device, or array of such devices, to partially ionize a gas to form a microplasma. The ionized gas can be a mixture of a noble gas, such as neon or argon, and hydrogen (H). The ionized gas can form a effluent stream directed onto the surface of a sample to desorb molecules from the remainder of the sample. The desorbed molecules can be ionized by the effluent stream as they leave the surface of the sample. The ionization process can include: photoionization, penning ionization, chemical ionization (proton transfer), and electron impact ionization. The ionized particles from the sample can be directed to a mass spectrometer for analysis. This can produce spatially-resolved mass spectral data, and can be conducted concurrently with another imaging system, such as a microscope.

System and method for spatially-resolved chemical analysis using microplasma desorption and ionization of a sample

Disclosed are apparatus and methods for depositing solvent-free molecules on surfaces of samples, with particular application to imaging mass spectrometry. A vacuum chamber is configured to have controllable matrix translation apparatus for controlling the position of one or more solvent-free matrices within the chamber. Sublimation apparatus is used to sublimate molecules from the solid phase matrices. One or more samples are placed separately from the solvent-free matrices within the chamber. Condensation apparatus individually cools the samples to deposit sublimated molecules on the samples. Controllable sample translation apparatus is used to control the position of the samples within the chamber. Rotatable sample holding apparatus may be used to hold and move the samples to allow deposition of molecules on multiple samples at substantially the same time. Rotatable matrix holding apparatus may also be used to hold and move a plurality of matrices to create a homogenous mixture of molecules that are deposited onto one or more samples. As surface characterization system may be used to monitor deposition of the molecules to determine their thickness and roughness. A computer may be configured to control the matrix translation apparatus, the sublimation apparatus, the condensation apparatus, and the sample translation apparatus to provide for automated deposition of solvent-free molecules on the samples.

Method and apparatus of uniform gas-phase molecular matrix deposition for imaging mass spectrometry

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Atlanta, GA, United States of America

Thomas Michael Orlando