Method and system for transfer printing of films

Patent metadata

Field	Value
Publication number	US-12167541-B2
Application number	US-202017793910-A
Country	US
Kind code	B2
Filing date	Nov 20, 2020
Priority date	Jan 27, 2020
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

The capillary transfer technology presented here represents a powerful approach to transfer soft films from surface of liquid onto a solid substrate in a fast and defect-free manner. The fundamental theoretical model and transfer criteria validated with comprehensive experiments and finite element analyses, for the first time provides a quantitative guide and optimization for the choice of material systems, operating conditions and environments for scalable on-demand transfers with high yield. The intrinsically moderate capillary transfer force and externally selectable transfer direction offer robust capabilities for achieving deterministic assembly and surface properties of structures with complex layouts and patterns for potentially broad applications in the fabrication of flexible/stretchable electronics, surface wetting structures and optical devices. Integration of this technology with other advanced manufacturing technologies associated with material self-assembly, growth and layout alignment represents promising future topics and would help create emerging new manufacturing technologies that leverage unique fluidity of liquid environments.

First claim

What is claimed is:

1. A transfer printing method for adhering a film onto a substrate, comprising:
placing said film on the surface of a liquid so that said film floats or otherwise rests on the surface of the liquid, said film including a proximal edge and a distal edge;
wherein the y-axis is defined as perpendicular to the plane of the surface of the liquid, wherein below the plane of the surface of the liquid is the negative y-axis and above the plane of the surface of the liquid is the positive y-axis;
moving said film and said substrate relative to one another until at initial contact said proximal edge of said film makes contact with said substrate across a transfer front (P) of said substrate;
advancing or retracting said substrate at a specified velocity (U), with a specified force (F), relative to the location of the liquid and at a specified substrate angle (a) relative to the negative y-axis so that said film elastically deforms onto said advancing or retracting substrate due to capillary force between the liquid and said film; and
detaching said film from the surface of the liquid and adhering said film onto said advancing or retracting substrate along said transfer front P, wherein said film gradually transits across the transfer front (P) among said advancing or retracting substrate, wherein said transfer front (P) is defined as a single line segment or arc wherein said substrate, said film, and the surface of the liquid all simultaneously intersect one another and physically contact one another.

2. The method of claim 1 , wherein said specified velocity of advancing or retracting said substrate is a constant velocity.

3. The method of claim 1 , wherein said specified velocity of advancing or retracting said substrate is a variable velocity.

4. The method of claim 1 , wherein said specified force of advancing or retracting said substrate is a constant force.

5. The method of claim 1 , wherein said specified force of advancing or retracting said substrate is a variable force.

6. The method of claim 1 , wherein said film is a flexible material defined as a material having a Young's modulus that is within any one of the following ranges:
about 0.1 kPa to 1 Pa;
1 kPa to 1 MPa;
1 MPa to 1 GPa; or
1 Pa to about 1 TPa.

7. The method of claim 1 , wherein said film is a flexible material defined as a material having a Young's modulus of about 2 MPa.

8. The method of claim 1 , wherein said film is a flexible material defined as a material having a bending stiffness (B) that is within any one of the following ranges:
0 N*m to 0.007 N*m; or
0.007 N*m to 0.014 N*m.

9. The method of claim 1 , wherein said film is a flexible material defined as a material having a bending stiffness (B) of about 0.001 N*m.

10. The method of claim 1 , wherein said film is a flexible material defined as a material having a bending stiffness (B) of about 0.01 N*m.

11. The method of claim 1 , wherein said film is a flexible material defined as a material having a bending stiffness (B) of about 0.014 N*m.

12. The method of claim 1 , wherein said specified substrate angle (α) of advancing or retracting substrate is a variable angle.

13. The method of claim 1 , wherein said specified substrate angle (α) of advancing or retracting substrate is a constant angle.

14. The method of claim 1 , wherein said film is in a shape of a geometric pattern.

15. The method of claim 1 , wherein said film is an electrical or electro-mechanical device.

16. The method of claim 1 , wherein said film has two-dimensional or three-dimensional designs.

17. The method of claim 16 , wherein said one or more two-dimensional or three-dimensional designs comprises any one or more of the following:
logo, letters, numbers, kirigami, or other specified pattern.

18. The method of claim 17 , wherein said specified pattern comprises any one or more of the following: electrical pattern, electronic pattern, electrical circuit, electronic circuit, or electro-mechanical feature.

19. The method of claim 1 , wherein said film includes one or more voids or is otherwise missing material.

20. The method of claim 19 , wherein the volume of said one or more voids relative to the volume of said film has a void to film ratio of any one of the following:
range of about 0.1% to about 40%;
range of about 1% to about 20%;
range of about 1% to about 10%; or
about 10%.

21. The method of claim 19 , wherein said one or more voids comprises any one or more of the following: recess, aperture, trough, pocket, channel, groove, bubble, hollowed-out portion, hollowed-out chamber.

22. The method of claim 1 , wherein said film is a composite material including two or more distinct materials as part of its composition.

23. The method of claim 1 , wherein said substrate has a flat surface.

24. The method of claim 1 , wherein said substrate has a convex, concave, or otherwise irregular or non-flat surface.

25. The method of claim 1 , wherein said substrate is a flexible material defined as a material having a Young's modulus that is within any one of the following ranges:
about 0.1 kPa to 1 Pa;
1 kPa to 1 MPa;
1 MPa to about 1 GPa; or
1 GPa to about 1 TPa.

26. The method of claim 1 , wherein said substrate is a flexible material defined as a material having a Young's modulus of about 2 MPa.

27. The method of claim 1 , wherein said substrate is a flexible material defined as a material having a Young's modulus of about 3 MPa.

28. The method of claim 1 , wherein said substrate is a rigid material defined as a material having a Young's modulus is within any one of the following ranges:
greater than about 3 MPa to 1 TPa;
1 TPa to 1.2 TPa; or
1.2 TPa to about 2 TPa.

29. The method of claim 1 , wherein a specified static contact angle (θ sl s ) between the liquid and said substrate is a value for said advancing said substrate that is between about 450 and about 180°.

30. The method of claim 1 , wherein a specified static contact angle (θ sl s ) between the liquid and said substrate is a value for said retracting substrate that is between about 0° and about 130 0 .

31. The method of claim 1 , wherein said specified substrate angle (α) is between about −90° and about 90° relative to the negative y-axis.

32. The method of claim 1 , wherein said film is a solid film.

33. The method of claim 1 , wherein said film is placed on the liquid while adhered to a tape.

34. The method of claim 33 , further comprising:
dissolving or removing said tape.

35. The method of claim 1 , wherein said substrate is a composite material including two or more distinct materials as part of its composition.

36. A transfer printed film disposed on said substrate prepared by the method of claim 1 .

Assignees

• Univ Virginia Patent Foundation

Inventors

• Xu Baoxing
• Zhang Yue

Classifications

• B44C1/1752 Primary

  Decalcomanias provided with a particular decorative layer, e.g. being specially adapted to allow the formation of a metallic or dyestuff layer on a substrate unsuitable for direct deposition (B44C1/1756, B44C1/1758 take precedence) · CPC title

• H05K2203/0776

  Uses of liquids not otherwise provided for in H05K2203/0759 - H05K2203/0773 · CPC title

• H05K2201/0323

  Carbon · CPC title

• H05K2201/026

  Nanotubes or nanowires · CPC title

• H05K2201/0162

  Silicon containing polymer, e.g. silicone · CPC title