ELECTRONIC SMOKING ARTICLE COMPRISING ONE OR MORE MICROHEATERS

• US 20140060554A1
• Filed: 09/04/2012
• Published: 03/06/2014
• Est. Priority Date: 09/04/2012
• Status: Active Grant

• Current Assignee: RAI STRATEGIC HOLDINGS, INC. (British American Tobacco PLC)
• Original Assignee: R J Reynolds Tobacco Company (R. J. Reynolds Tobacco)
• Inventors: Collett, William Robert, Sears, Stephen Benson, Potter, Dennis Lee, Alderman, Steven Lee, Kebaili, Mo
• Granted Patent: US 8,881,737 B2
• Time in Patent Office: Days
• US Class Current: 131/328
• CPC Class Codes: A24F 40/10 Devices using liquid inhalable precursors
• CPC Class Codes: A24F 40/20 Devices using solid inhalable precursors
• CPC Class Codes: A24F 40/30 Devices using two or more structurally separated inhalable precursors, e.g. using two liquid precursors in two cartridges
• CPC Class Codes: A24F 40/42 Cartridges or containers for inhalable precursors
• CPC Class Codes: A24F 40/46 Shape or structure of electric heating means
• CPC Class Codes: A24F 40/51 Arrangement of sensors
• CPC Class Codes: H05B 2203/003 using serpentine layout
• CPC Class Codes: H05B 3/265 the insulating base being an inorganic material, e.g. ceramic H05B3/262 takes precedence

Abstract

The present disclosure relates to an electronic smoking article that provides for improved aerosol delivery. Particularly, the article comprises one or more microheaters. In various embodiments, the microheaters provide for improved control of vaporization of an aerosol precursor composition and provide for reduced power requirements to achieve consistent aerosolization. The present disclosure further relates to methods of forming an aerosol in a smoking article.

Claims

1. A smoking article comprising an electrical power source and a microheater in electrical connection with the electrical power source.

2. The smoking article of claim 1, wherein the microheater is a Micro-Electro-Mechanical Systems (MEMS) based heater.

3. The smoking article of claim 1, wherein the microheater is a thin film heater.

4. The smoking article of claim 1, wherein the microheater comprises a patterned, electrically conductive material.

5. The smoking article of claim 4, wherein the electrically conductive material is selected from the group consisting of elemental metals, metal alloys, silicon, ceramics, carbon, carbides, nitrides, and combinations thereof.

6. The smoking article of claim 4, wherein the electrically conductive material is an elemental metal or metal alloy.

7. The smoking article of claim 4, wherein the microheater comprises a supporting layer upon which the electrically conductive material is patterned.

8. The smoking article of claim 7, wherein the electrically conductive material is a printed layer overlying the supporting layer.

9. The smoking article of claim 7, wherein the electrically conductive material is an etched layer overlying the supporting layer.

10. The smoking article of claim 7, wherein the supporting layer is temperature stable in a temperature range of about 125°

C. to about 750°

C.

11. The smoking article of claim 7, wherein the supporting layer comprises a silicon-based material.

12. The smoking article of claim 11, wherein the supporting layer comprises silicon nitride.

13. The smoking article of claim 4, wherein the microheater comprises a protective layer overlying the patterned, electrically conductive material.

14. The smoking article of claim 13, wherein the protective layer is temperature stable in a temperature range of about 125°

C. to about 750°

C.

15. The smoking article of claim 13, wherein protective layer comprises a silicon-based material.

16. The smoking article of claim 15, wherein the protective layer comprises silicon dioxide.

17. The smoking article of claim 1, wherein the microheater comprises two or more layers.

18. The smoking article of claim 1, wherein the microheater comprises an electrically conductive material sandwiched between two membranes.

19. The smoking article of claim 1, wherein the microheater has a length of up to about 3 mm and a width of up to about 3 mm.

21. The smoking article of claim 1, wherein the microheater is attached to a substrate.

22. The smoking article of claim 21, wherein the substrate is removable from the smoking article.

23. The smoking article of claim 21, wherein the substrate is formed of an electrically insulating material.

24. The smoking article of claim 1, comprising a plurality of microheaters.

25. The smoking article of claim 24, wherein the plurality of microheaters are serially aligned within the smoking article.

26. The smoking article of claim 1, further comprising an aerosol precursor composition.

27. The smoking article of claim 26, wherein the microheater is operatively positioned within the smoking article to be substantially in contact with the aerosol precursor composition.

28. The smoking article of claim 26, wherein the aerosol precursor composition is in the form of a liquid or gel at ambient conditions.

29. The smoking article of claim 28, wherein the aerosol precursor composition is in the form of a gel, and wherein the gel is coated on the microheater.

30. The smoking article of claim 28, wherein the aerosol precursor composition is in a reservoir such that the aerosol precursor composition is separated from the microheater.

31. The smoking article of claim 30, wherein the article comprises a controller adapted to actuate delivery of a defined volume of the aerosol precursor composition to the microheater.

32. The smoking article of claim 30, wherein the microheater is in thermal connection with a chamber, the chamber being adapted to receive an aliquot of the aerosol precursor composition through an opening in the chamber.

33. The smoking article of claim 32, wherein the chamber includes an opening adapted for the exit of vapor from the chamber.

34. The smoking article of claim 32, wherein the chamber has a volume of about 0.2 ml to about 1 ml.

35. The smoking article of claim 32, wherein the aerosol precursor composition comprises of a plurality of separate components, wherein the smoking article comprises a plurality of reservoirs separately containing the separate components of the aerosol precursor composition, and wherein the smoking article comprises a plurality of chambers adapted to receive aliquots of the separate components of the aerosol precursor composition from the reservoirs.

36. The smoking article of claim 26, wherein the aerosol precursor composition is coated on, adsorbed by, or absorbed in a carrier material.

37. The smoking article of claim 36, wherein the carrier material is positioned within the article to be in substantial contact with the microheater.

38. The smoking article of claim 37, wherein the article comprises a plurality of microheaters that are in substantial contact with the carrier material.

39. The smoking article of claim 26, wherein the aerosol precursor composition comprises a polyhydric alcohol.

40. The smoking article of claim 26, wherein the aerosol precursor composition comprises a medicament.

41. The smoking article of claim 26, wherein the aerosol precursor composition comprises a tobacco component or a tobacco-derived material.

42. The smoking article of claim 26, wherein the aerosol precursor composition comprises a flavorant.

43. The smoking article of claim 1, wherein the electrical power source is selected from the group consisting of a battery, a capacitor, and combinations thereof.

44. The smoking article of claim 1, wherein the article comprises a control component that actuates current flow from the electrical power source to the microheater.

45. The smoking article of claim 44, wherein the control component comprises a puff-actuated sensor.

46. The smoking article of claim 45, wherein the control component comprises a capacitive sensor.

47. The smoking article of claim 1, wherein the microheater is integral with an atomizer.

48. The smoking article of claim 47, wherein the atomizer comprises a chamber defined by a wall, a cover, and a protective layer overlying the microheater.

49. The smoking article of claim 48, wherein one or both of the wall and the cover include a plurality of openings sized such that vapor passes therethrough but such that liquid does not pass therethrough.

20. The smoking article of clam 1, wherein the microheater has a length of about 0.5 mm to about 3 mm and a width of about 0.5 mm to about 3 mm.

50. A method of forming an aerosol in a smoking article, the method comprising initiating current flow from an electrical power source within the smoking article to a microheater within the smoking article so as to cause heating of the microheater and an aerosol precursor composition contacting the microheater.

51. The method of claim 50, wherein the smoking article comprises a plurality of microheaters.

52. The method of claim 51, wherein two or more of the microheaters are simultaneously heated.

53. The method of claim 52, wherein the aerosol precursor composition comprises two or more separate components, and wherein the separate components of the aerosol precursor composition are separately heated by the simultaneously heated microheaters.

54. The method of claim 52, wherein the simultaneously heated microheaters receive current flow from the electrical power source under different conditions such that the microheaters are heated to different temperatures or are heated for different amounts of time.

55. The method of claim 51, wherein two or more of the microheaters are heated serially.

56. The method of claim 51, wherein the aerosol precursor composition is coated on, adsorbed by, or absorbed in a carrier material, and wherein prior to the step of initiating current flow, the method further comprises inserting the carrier material into the smoking article.

57. The method of claim 51, wherein the microheaters are attached to a substrate, and wherein prior to the step of initiating current flow, the method further comprises inserting the substrate into the smoking article.

58. The method of claim 57, wherein the aerosol precursor composition is coated on the microheaters attached to the substrate.

59. The method of claim 50, further comprising initiating flow of the aerosol precursor composition from a reservoir to a chamber that is in thermal connection with the microheater so as to heat the aerosol precursor composition within the chamber.

60. An atomizer suitable for use in an electronic smoking article, the atomizer comprising a chamber formed of a chamber wall, a cover, and a microheater.

61. The atomizer of claim 60, wherein one or both of the chamber wall and the cover include a plurality of openings sized such that vapor passes therethrough but such that liquid does not pass therethrough.