Articles for manipulating impinging liquids and methods of manufacturing same

1. An article comprising a non-wetting surface having a dynamic contact angle of at least about 90°, said surface comprising non-wetting features, said surface patterned with macro-scale features having a length scale L m that is larger than a length scale L n of the non-wetting features, the macro-scale features being configured to induce controlled asymmetry in a liquid film produced by impingement of a droplet onto the surface, thereby reducing contact time t c between the droplet and the surface to a value lower than

2.2(( ρR^ 3)/γ)^(½)(1+φ/4)

where the droplet has a radius R, density ρ, surface tension γ, and the patterned surface having a pinning fraction φ of zero.

2. The article of claim 1 , wherein the non-wetting surface is superhydrophobic.

3. The article of claim 1 , wherein the non-wetting surface is superoleophobic.

4. The article of claim 1 , wherein the non-wetting surface is supermetallophobic.

5. The article of claim 1 , wherein the non-wetting features are nanoscale pores.

6. The article of claim 1 , wherein the surface is heated above its Leidenfrost temperature.

7. The article of claim 1 , wherein the macro-scale features comprise ridges having height A r and spacing λ r , with A r /h greater than about 0.01 and λ r /A r greater than or equal to about 1, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

8. The article of claim 1 , wherein the macro-scale features comprise ridges having height A r and spacing λ r , with A r /h from about 0.01 to about 100 and λ r /A r greater than or equal to about 1, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

9. The article of claim 1 , wherein the macro-scale features comprise ridges having height A r and spacing λ r , with A r /h from about 0.1 to about 10 and λ r /A r greater than or equal to about 1, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

10. The article of claim 1 , wherein the article is a wind turbine blade, the macro-scale features comprise ridges having height A r and spacing λ r , and wherein 0.0001 mm<A r and λ r ≧0.0001 mm.

11. The article of claim 1 , wherein the article is a rainproof product, the macro-scale features comprise ridges having height A r and spacing λ r , and wherein 0.0001 mm<A r and λ r ≧0.0001 mm.

12. The article of claim 1 , wherein the article is a steam turbine blade, the macro-scale features comprise ridges having height A r and spacing λ r , and wherein 0.00001 mm<A r and λ r ≧0.0001 mm.

13. The article of claim 1 , wherein the article is an exterior aircraft part, the macro-scale features comprise ridges having height A r and spacing λ r , and wherein 0.00001 mm<A r and λ r ≧0.0001 mm.

14. The article of claim 1 , wherein the article is a gas turbine blade, the macro-scale features comprise ridges having height A r and spacing λ r , and wherein 0.00001 mm<A r and λ r ≧0.0001 mm.

15. The article of claim 1 , wherein the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , with A p /h>0.01 and λ p /A p ≧2, wherein h is lamella thickness of the droplet upon impingement onto the surface.

16. The article of claim 1 , wherein the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , with 100>A p /h>0.01 and λ p /A p ≧2, wherein h is lamella thickness of the droplet upon impingement onto the surface.

17. The article of claim 1 , wherein the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , with 10>A p /h>0.1 and λ p /A p ≧2, wherein h is lamella thickness of the droplet upon impingement onto the surface.

18. The article of claim 1 , wherein the macro-scale features are hemispherical protrusions.

19. The article of claim 1 , wherein the article is a wind turbine blade, the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , and wherein 0.0001 mm<A p and λ p ≧0.0002 mm.

20. The article of claim 1 , wherein the article is a rainproof product, the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , and wherein 0.0001 mm<A p and λ p ≧0.0002 mm.

21. The article of claim 1 , wherein the article is a steam turbine blade, the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , and wherein 0.00001 mm<A p and λ p ≧0.00002 mm.

22. The article of claim 1 , wherein the article is an exterior aircraft part, the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , and wherein 0.00001 mm<A p and λ p ≧0.00002 mm.

23. The article of claim 1 , wherein the article is a gas turbine blade, the macro-scale features comprise protrusions having height A p and whose centers are separated by a distance λ p , and wherein 0.00001 mm<A p and λ p ≧0.00002 mm.

24. The article of claim 1 , wherein the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , with A c /h>0.01 and λ c /A c ≧2, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

25. The article of claim 1 , wherein the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , with 100>A c /h>0.01 and 500≧λ c /A c ≧2, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

26. The article of claim 1 , wherein the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , with 50>A c /h>0.1 and 500≧λ c /A c ≧2, wherein h is lamella thickness of the droplet upon droplet impingement onto the surface.

27. The article of claim 1 , wherein the article is a rainproof product, the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , and wherein 0.0001 mm<A c and λ c ≧0.0002 mm.

28. The article of claim 1 , wherein the article is a wind turbine blade, the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , and wherein 0.0001 mm<A c and λ c ≧0.0002 mm.

29. The article of claim 1 , wherein the article is a steam turbine blade, the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , and wherein 0.00001 mm<A c and λ c ≧0.00002 mm.

30. The article of claim 1 , wherein the article is an exterior aircraft part, the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , and wherein 0.00001 mm<A c and λ c ≧0.00002 mm.

31. The article of claim 1 , wherein the article is a gas turbine blade, the macro-scale features comprise a sinusoidal profile having amplitude A c and period λ c , and wherein 0.00001 mm<A c and λ c ≧0.00002 mm.

32. The article of claim 1 , wherein the surface comprises an alkane.

33. The article of claim 1 , wherein the surface comprises a fluoropolymer.

34. The article of claim 1 , wherein the surface comprises at least one member selected from the group consisting of teflon, trichloro(1H,1H,2H,2H-perfluorooctyDsilane (TCS), octadecyltrichlorosilane (OTS), heptadecafluoro-1,1,2,2-tetrahydrodecyltrichlorosilane, fluoroPOSS, a ceramic material, a polymeric material, a fluorinated material, an intermetallic compound, and a composite material.

35. The article of claim 1 , wherein the surface comprises a polymeric material, the polymeric material comprising at least one of polytetrafluoroethylene, fluoroacrylate, fluorourethane, fluorosilicone, fluorosilane, modified carbonate, chlorosilanes, and silicone.

36. The article of claim 1 , wherein the surface comprises a ceramic material, the ceramic material comprising at least one of titanium carbide, titanium nitride, chromium nitride, boron nitride, chromium carbide, molybdenum carbide, titanium carbonitride, electroless nickel, zirconium nitride, fluorinated silicon dioxide, titanium dioxide, tantalum oxide, tantalum nitride, diamond-like carbon, and fluorinated diamond-like carbon.

37. The article of claim 1 , wherein the surface comprises an intermetallic compound, the intermetallic compound comprising at least one of nickel aluminide and titanium aluminide.

38. The article of claim 1 , wherein the article is a condenser.

39. The article of claim 1 , wherein the article is a drip shield for storage of radioactive material.

40. The article of claim 1 , wherein the article is a self-cleaning solar panel.

41. The article of claim 1 , wherein L m /L n is greater than 10.

42. The article of claim 1 , wherein L m /L n is greater than 100.

43. The article of claim 1 , wherein L m /L n is greater than 1000.

44. The article of claim 1 , wherein L m /L n is greater than 10,000.

45. The article of claim 1 , wherein the non-wetting features having the length scale L n comprise non-wetting features having a second scale disposed thereon, wherein the second scale is smaller than L n .

46. The article of claim 45 , wherein L m /L n is greater than 10.

47. The article of claim 46 , wherein L m /L n is greater than 100.

48. The article of claim 1 , wherein the macro-scale features comprise non-wetting features thereon.

49. The article of claim 48 , wherein the non-wetting features comprise non-wetting features having a second scale disposed thereon, wherein the second scale is smaller than L n .

50. The article of claim 1 , wherein the contact time t c is more than 50% below 2.2((ρR^3)/γ)^(½)(1+φ/4).

51. The article of claim 1 , wherein the non-wetting features comprise random or patterned surface roughness.