Transferring graphitic thin films with a liquid gallium probe

{
  "publication_number": "US10857774B2",
  "country": "US",
  "kind": "B2",
  "title": "Transferring graphitic thin films with a liquid gallium probe",
  "abstract": "The present invention generally relates to a process for transferring a graphitic thin film and a kit for the same.",
  "claims": [
    "1. A method of transferring a graphitic thin film, comprising: (a) contacting a liquid-suspended graphitic thin film with a liquid gallium probe, wherein the graphitic thin film adheres to the liquid gallium of the probe to form a gallium-suspended graphitic thin film; and, (b) transferring the graphitic thin film to a substrate by contacting the graphitic thin film with the substrate, wherein the graphitic thin film adheres to the substrate to form a graphitic thin film-coated substrate.",
    "2. The method of claim 1, wherein the graphitic thin film is suspended in water.",
    "3. The method of claim 1, wherein the substrate of step (b) is an oxidized Si wafer.",
    "4. The method of claim 1, wherein contacting and transferring are performed with a micromanipulator.",
    "5. The method of claim 1, wherein liquid gallium probe, comprises: (i) a shank with 1 st and 2 nd ends; (ii) a loop attached to the 1 st end of the shank; (iii) a drop of gallium in contact with the loop; and (iv) a heat source capable of liquefying gallium.",
    "6. The method of claim 5, wherein the heat source, comprises: a coil of resistance wire surrounding, but not touching the shank and in close enough proximity to the gallium drop to liquefy it.",
    "7. The method of claim 5, wherein the heat source, comprises: a plurality of coils of resistance wire surrounding, but not touching the shank and in close enough proximity to the gallium drop to liquefy it.",
    "8. The method of claim 1, wherein the process, prior to step (a), further comprises: (a1) placing a graphitic-metal material, comprising: the graphitic thin film and a metal layer, into a 1 st chamber of an etching container, comprising: (i) a 1 st chamber comprising: an etchant solution, a 1 st port, and a 2 nd port, wherein the etchant level is above the level of the ports and is in contact with the metal layer of the graphitic-metal material; (ii) a 2 nd chamber adjacent to the 1 st chamber, comprising: the etchant solution and a 1 st port in liquid contact with the 1 st port of the 1 st chamber, wherein the etchant level is above the level of the 1 st port; and, (iii) a 3 rd chamber adjacent to the 1 st chamber, comprising: the etchant solution and a 1 st port in liquid contact with the 2 nd port of the 1 st chamber, wherein the etchant level is above the level of the 1 st port; (a2) inserting, after the etchant has dissolved the metal layer of the graphitic-metal sample, a first end of a siphon below the etchant level of the 2 nd chamber and the second end into a water-containing fluid level regulation container, (a3) introducing water into the 3 rd chamber at a rate and amount sufficient to replace the etchant in the 1 st chamber with water by causing; (i) the etchant solution to exit the 3 rd chamber and enter the 1 st chamber; (ii) the etchant solution to exit the 1 st chamber and enter the 2 nd chamber; and, (iii) the etchant solution to exit the 2 nd chamber and into the fluid level regulation container via the siphon.",
    "9. The method of claim 8, further comprising: (a4) locating the resulting graphitic thin film with a Brewster's Angle Microscope.",
    "10. The method of claim 1, wherein the process, prior to step (b), further comprises: (a5) heating the gallium to a temperature sufficient to liquefy it.",
    "11. The method of claim 8, wherein the process, prior to step (b), further comprises: (a5) heating the gallium to a temperature sufficient to liquefy it.",
    "12. The method of claim 9, wherein the process, prior to step (b), further comprises: (a5) heating the gallium to a temperature sufficient to liquefy it.",
    "13. The method of claim 8, wherein the metal layer of step (a1) is copper.",
    "14. The method of claim 8, wherein the etchant solution of step (a1)(i) is 1M ferric chloride."
  ],
  "description_excerpt": "The present invention generally relates to a process for transferring a graphitic thin film and a kit for the same.\n\nThe transfer of graphitic thin films from one surface to another is hindered by one or more of the following: 1) the films are brittle, being typically from one to ten atoms thick; 2) graphitic thin films are difficult to locate with the unaided eye, being nearly completely transparent to white light; and, 3) current transfer methods involve the application of polymers such as polymethyl methacrylate (PMMA) or polyethylene terephthalate (PET), contaminating the film.\n\nIn view of the above, it would be advantageous to discover new ways of transferring graphitic thin films.\n\nIn an aspect, the present invention provides a novel method of transferring a graphitic thin film.\n\nIn another aspect, the present invention provides a novel kit for transferring a graphitic thin film.\n\nThese and other aspects, which will become apparent during the following detailed description, have been achieved by the inventors' discovery that liquid gallium can be used to transfer a graphitic thin film.\n\nFIG. 1 is a drawing of a three-chamber etching container useful in the present invention.\n\nFIG. 2 is a photograph of a three-chamber etching container.\n\nFIG. 3 is a photograph of a Brewster's angle microscope with etching container.\n\nFIG. 4 is a photograph of a gallium probe on the end of a micromanipulator.\n\nFIG. 5 shows before and after Raman spectra.\n\nFIG. 1 shows a drawing of a three-chamber etching container useful in the present invention, wherein the chambers are interconnected by a tube (or ports) (dimensions are in inches).",
  "cpc": [
    "B32B 37/025",
    "B25J 7/00",
    "B32B 2037/243",
    "B32B 2264/108",
    "B32B 37/24",
    "B32B 38/10",
    "B32B 9/007",
    "C23F 1/08",
    "C23F 1/18"
  ],
  "ipc": [
    "B32B 37/00",
    "B32B 37/24",
    "B32B 38/10",
    "B32B 9/00",
    "C23F 1/08",
    "C23F 1/18"
  ],
  "assignees": [
    "Vaon LLC"
  ],
  "inventors": [
    "John Gilbert",
    "Henry Steen",
    "Keith Andrew",
    "Richard C Pape"
  ],
  "filing_date": "2018-11-20",
  "publication_date": "2020-12-08",
  "grant_date": "2020-12-08",
  "priority_date": "2017-11-21",
  "application_number": "US-201816196187-A",
  "family_id": "66534855",
  "cited_by_count": 0,
  "citations": [
    "US20120082737A1",
    "US20130272951A1",
    "CN107808819A"
  ]
}