Direct printing and writing using undercooled metallic core-shell particles

1. A method of direct printing or writing of a metallic material, comprising:

using a printing device or a writing device to deposit an ink comprising undercooled liquid metallic core-shell particles dispersed in a carrier fluid on a substrate surface as one or more layers, the undercooled liquid metallic core-shell particles comprising a liquid metallic core material;

wherein

the substrate surface comprises a thermoplastic material, a thermoset material, an amorphous material, a porous material, a fibrous material, or a combination thereof, or

the carrier fluid comprises a cellulose solution, or

a combination thereof.

2. The method of claim 1 including relatively moving the substrate surface and the printing or writing device to deposit the undercooled liquid metallic core-shell particles on the substrate surface.

3. The method of claim 1 including the additional step of releasing the liquid metallic core material of the undercooled liquid metallic core-shell particles and solidifying the released liquid metallic material as one or more metallic layers on the substrate surface.

4. The method of claim 3 wherein the one or more metallic layers is/are electrically conductive.

5. The method of claim 1 wherein the one or more layers is/are thermally conductive.

6. The method of claim 1 where the one or more layers is/are continuous, porous or discontinuous.

7. The method of claim 1 wherein the one or more layers form one or more straight or curvilinear electrically conductive lines.

8. The method of claim 7 wherein the lines are laterally spaced apart on the substrate surface.

9. The method of claim 7 where the lines are orthogonally positioned.

10. The method of claim 7 where the lines intersect at an angle.

11. The method of claim 7 wherein the lines are disposed one atop the other as a 3-D line.

12. The method of claim 1 wherein the writing device comprises a writing pen.

13. The method of claim 1 wherein the writing device comprises a printer.

14. The method of claim 1 where in the writing device is a tube through which the ink flows out.

15. The method of claim 14 where the tube communicates with a pump to provide a microfluidic delivery system.

16. The method of claim 13 where a flow focus nozzle is attached to the tube.

17. The method of claim 3 wherein the liquid metallic core material is released by removing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

18. The method of claim 17 including using a chemical flux to release the metallic core material from the undercooled liquid metallic core-shell particles by removing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

19. The method of claim 3 including mechanically fracturing at least some of the particle to release the metallic core material.

20. The method of claim 19 where a fracture force is applied using the printing device or the writing device.

21. The method of claim 19 where the fracture force is applied using a tool that includes at least one of a roller, a press, and a blunt object.

22. The method of claim 3 including using light impingement to at least release the metallic core material from the undercooled liquid metallic core-shell particles by removing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

23. The method of claim 22 wherein the light is a laser.

24. The method of claim 22 wherein the light is a focused beam.

25. The method of claim 3 including using ultrasound to release the metallic core material from the undercooled liquid metallic core-shell particles by removing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

26. The method of claim 3 including using vibration to release the metallic core material from the undercooled liquid metallic core-shell particles by removing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

27. The method of claim 3 including using heat to release the metallic core material from the undercooled liquid metallic core-shell particles by fracturing at least part of a particle shell of at least some of the undercooled liquid metallic core-shell particles.

28. The method of claim 1 wherein the substrate surface comprises a polymer or gel.

29. The method of claim 1 wherein the substrate surface comprises a thermoplastic material.

30. The method of claim 1 wherein the substrate surface comprises a thermoset material.

31. The method of claim 1 wherein the substrate surface comprises a glass material.

32. The method of claim 1 wherein the substrate surface comprises a metal material.

33. The method of claim 1 wherein the substrate surface comprises a composite material.

34. The method of claim 1 wherein the substrate surface comprises a ceramic material.

35. The method of claim 1 wherein the substrate surface comprises a crystalline material.

36. The method of claim 1 wherein the substrate surface comprises an amorphous material.

37. The method of claim 1 wherein the substrate surface comprises a porous material.

38. The method of claim 1 wherein the substrate surface comprises a fibrous material.

39. The method of claim 1 wherein the one or more layers have a shape of a contact pad or touch pad.

40. The method of claim 1 , further comprising forming an electronic device that comprises the substrate surface, wherein the one or more layers comprise electrically interconnected, solidified metallic particle material.

41. The method of claim 40 , wherein the electronic device comprises at least one of a LED device, a MEMS device, a capacitance touch sensor, and a Wheatstone bridge.

42. The method of claim 1 wherein the substrate surface is a flexible substrate surface.

43. The method of claim 1 wherein the core-shell particles each comprise a liquid metallic core within an outer oxide shell.

44. The method of claim 1 wherein the carrier fluid is a cellulose solution.