Method and apparatus for aerosol-based three-dimensional (3D) printing of flexible graphene electronic devices
The disclosure is directed at a method and system for three-dimensional (3D) printing of flexible graphene electronic devices and deposition of graphene on non-planar surfaces. By using a printer ink that includes a stabilized graphene powder and a pair of solvents, the printer ink provides for a material that overcomes disadvantages of current systems. In one embodiment, the pair of solvents are cyclohexanone and terpineol. The stabilized graphene powder preferably includes a polymer such as, but not limited to ethyl cellulose.
1. A method of three-dimensional (3D) printing of a flexible graphene electronic device comprising:
producing a printer ink solution, for use in aerosol-based printing, the printer ink solution including a stabilized graphene powder, a first solvent able to dissolve a high concentration of graphene within the stabilized graphene powder and having a surface tension for use in 3D printing; and a second solvent having a high viscosity, a high boiling point and able to dissolve the graphene within the stabilized graphene powder wherein a size of graphene flakes within the stabilized graphene powder is less than about 200 nm;
generating a mist of atomized particles of the aerosol-based printer ink solution; and
delivering mist of atomized particles of the aerosol-based printer ink solution to a 3D printing apparatus.
2. The method of claim 1 further comprising:
3D printing the flexible graphene electronic device with the mist of atomized particles of the printer ink solution.
3. The method of claim 1 wherein producing the printer ink solution comprises:
exfoliating graphite in an alcohol to produce the graphite flakes in the alcohol;
adding stabilizing polymer to the graphite flakes in the alcohol;
drying the graphite flakes in the alcohol to produce the stabilized graphene powder;
mixing in the first solvent with the stabilized graphene powder; and
mixing in the second solvent to produce the printer ink solution.
4. The method of claim 3 wherein the first solvent is selected from a group consisting of cyclohexanone, ethanol and water.
5. The method of claim 3 wherein the second solvent is selected from a group consisting of terpineol and N-methylpyrrolidone (NMP).
6. The method of claim 3 further comprising, before drying the printer ink solution:
flocculating the graphite flakes in the alcohol.
7. The method of claim 3 wherein the second solvent is 5 to 15% by volume of the printer ink solution.
8. The method of claim 3 wherein exfoliating graphite in the alcohol comprises:
using sonication power to exfoliate the graphite.
9. The method of claim 8 wherein the alcohol is ethanol.
10. The method of claim 3 wherein the polymer is one of ethyl cellulose or polyvinylpyrrolidone.
11. The method of claim 3 further comprising:
applying a centrifugal force after exfoliating the graphite.
12. The method of Claim 8 wherein flocculating the graphite flakes in the alcohol comprises:
adding a salt solution to the graphite flakes in the alcohol.
13. The method of claim 3 further comprising:
determining a content of graphene after adding the stabilizing polymer.
14. The method of claim 3 further comprising:
filtering the stabilized graphene powder.
15. The method of claim 1 further comprising agitating the printer ink solution after producing the printer ink solution.