A TWO-LAYER MESH ELEMENT FOR AN ATOMISER ASSEMBLY

Abstract

A mesh element for an atomiser assembly is provided, including: a first layer defining at least one channel including a minimum cross-sectional area; and a second layer overlying the first layer and defining at least one nozzle including a maximum cross-sectional area, the second layer including an inner surface facing the first layer and an outer surface facing away from the first layer, the at least one nozzle overlying the at least one channel, and the maximum cross-sectional area of the at least one nozzle being smaller than the minimum cross-sectional area of the at least one channel, and the outer surface of the second layer defining an annular portion extending around the at least one nozzle, the annular portion having a semi-circular cross-sectional shape, and a thickness of the second layer at each annular portion being larger than a thickness of the second layer between adjacent annular portions.

Claims

1.-14. (canceled)

15. A mesh element for an atomiser assembly, the mesh element comprising: a first layer defining at least one channel, the at least one channel comprising a minimum cross-sectional area; and a second layer overlying the first layer, wherein the second layer defines at least one nozzle comprising a maximum cross-sectional area, and wherein the second layer comprises an inner surface facing the first layer and an outer surface facing away from the first layer, wherein the at least one nozzle overlies the at least one channel, and wherein the maximum cross-sectional area of the at least one nozzle is smaller than the minimum cross-sectional area of the at least one channel, and wherein the outer surface of the second layer defines an annular portion extending around the at least one nozzle, wherein the annular portion has a semi-circular cross-sectional shape, and wherein a thickness of the second layer at each annular portion is larger than a thickness of the second layer between adjacent annular portions.

16. The mesh element according to claim 15, wherein the at least one nozzle is a plurality of nozzles, and wherein the plurality of nozzles overlie the at least one channel.

17. The mesh element according to claim 16, wherein the at least one channel further comprises a plurality of channels, and wherein each channel of the plurality of channels underlies at least two of the nozzles.

18. The mesh element according to claim 15, wherein the first layer comprises a first thickness, wherein the second layer comprises a second thickness, and wherein the first thickness is larger than the second thickness.

19. The mesh element according to claim 15, wherein the at least one channel further comprises a first length, wherein the at least one nozzle further comprises a second length, and wherein the first length is larger than the second length.

20. The mesh element according to claim 19, wherein the at least one nozzle further comprises a first cross-sectional shape along a line extending parallel with the second length of the at least one nozzle, and wherein the first cross-sectional shape of the at least one nozzle is triangular.

21. The mesh element according to claim 15, further comprising a hydrophobic coating on the outer surface of the second layer.

22. The mesh element according to claim 15, wherein the first layer comprises a first surface facing away from the second layer and a second surface facing the second layer, and wherein the mesh element further comprises a hydrophilic coating on the first surface of the first layer.

23. The mesh element according to claim 15, further comprising an electrical heating element disposed on a surface of the first layer or the second layer.

24. The mesh element according to claim 23, wherein the electrical heating element comprises a microelectromechanical systems heating element.

25. An atomiser assembly for an aerosol-generating device, the atomiser assembly comprising: a mesh element according to claim 15; an elastically deformable element; a cavity defined between the mesh element and the elastically deformable element; a liquid inlet configured to provide a supply of liquid to be atomized to the cavity; and an actuator configured to oscillate the elastically deformable element.

26. The atomiser assembly according to claim 25, wherein the actuator comprises a piezoelectric element.

27. An aerosol-generating device, comprising: an atomizer assembly according to claim 25; a power supply; a controller configured to control a supply of power from the power supply to the actuator; and a connector configured to receive a liquid reservoir and to supply liquid from the liquid reservoir to the liquid inlet.

28. An aerosol-generating system, comprising: an aerosol-generating device according to claim 27; and a liquid reservoir containing a liquid aerosol-forming substrate.

Description

[0116] The invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0117] FIG. 1 shows a cross-sectional view of a mesh element according to an embodiment of the present invention;

[0118] FIG. 2 shows a plan view of the mesh element of FIG. 1;

[0119] FIG. 3 shows an enlarged cross-sectional view of a portion of the mesh element of FIG. 1;

[0120] FIG. 4 shows a cross-sectional view of a single nozzle of the mesh element of FIG. 1;

[0121] FIG. 5 shows a cross-sectional view of a single nozzle of the mesh element of FIG. 1 illustrating an alternative outer surface of the second layer;

[0122] FIG. 6 shows a perspective cross-sectional view of an atomiser assembly comprising the mesh element of FIG. 1; and

[0123] FIG. 7 shows a partially exploded cross-sectional view of an aerosol-generating system according to an embodiment of the present invention.

[0124] FIGS. 1 and 2 show a mesh element 10 according to an embodiment of the present invention. The mesh element 10 comprises a first layer 12 defining a plurality of cylindrical channels 14 and a second layer 16 defining a plurality of nozzles 18. The nozzles 18 are arranged into groups, wherein each group of nozzles 18 overlies one of the channels 14.

[0125] The mesh element 10 also comprises an electrical heating element 19 positioned on the second layer 16. During use, the electrical heating element 19 heats the mesh element 10, which heats liquid being ejected through the nozzles 18.

[0126] FIGS. 3 and 4 show enlarged cross-sectional views of one of the channels 14 and one of the nozzles 18. The first layer 12 comprises a first surface 20 and a second surface 22. The second layer 16 comprises an inner surface 24 facing the second surface 22 of the first layer 12. The second layer 16 also comprises an outer surface 26 on which a hydrophobic coating 28 is provided. The first and second layers 12, 16 are formed from silicon wafers. A buried oxide layer 30 is formed by oxidation of the second surface 22 of the first layer 12 before the first and second layers 12, 16 are bonded together during the manufacture of the mesh element 10.

[0127] Each channel 14 has a minimum diameter 32 and a length corresponding to a thickness 33 of the first layer 12. The minimum diameter 32 of each channel 14 is significantly larger than a maximum diameter 34 of each overlying nozzle 18. Therefore, each channel 14 has a minimum cross-sectional area that is larger than the maximum cross-sectional area of each nozzle 18. As such, the length of the channel 14 does not contribute to a length of each nozzle 18 when determining the pressure required to force a given liquid through each nozzle 18. Advantageously, the thickness 33 of the first layer 12 can be selected to provide the mesh element with a desired strength and rigidity without affecting the pressure required to eject liquid droplets from the nozzles 18.

[0128] Each nozzle 18 has a triangular cross-sectional shape such that each nozzle 18 has a maximum diameter 34 at the inner surface 24 of the second layer 16 and a minimum diameter 36 at the outer surface 26 of the second layer 16. The minimum diameter 36 of each nozzle 18 is selected according to the desired size of liquid droplets to be ejected through the nozzle 18 during use. Each nozzle 18 has a length corresponding to a thickness 38 of the second layer 16. The thickness 38 of the second layer 16 is significantly smaller than the thickness 33 of the first layer 12 to minimise the length of each nozzle 18. The triangular cross-sectional shape of each nozzle 18 and the minimised length of each nozzle 18 reduce or minimise the pressure required to force a given liquid through each nozzle 18.

[0129] As shown in FIG. 5, the outer surface 26 of the second layer 16 may comprise an annular portion 40 of increased thickness surrounding each nozzle 18. The semi-circular cross-sectional shape of each annular portion 40 facilitates separation of liquid droplets from liquid remaining inside each nozzle 18 during use.

[0130] FIG. 6 shows a perspective cross-sectional view of an atomiser assembly 50 comprising the mesh element 10 of FIG. 1. The mesh element 10 is received within a mesh element housing 52. The atomiser assembly 50 also comprises an elastically deformable element 54 and an actuator 56 arranged to oscillate the elastically deformable element 54. The actuator 56 is a piezoelectric actuator.

[0131] The atomiser assembly 50 also comprises a pre-loading element 58 arranged to compress the actuator 56 between the pre-loading element 58 and the elastically deformable element 54. The pre-loading element 58, the actuator 56 and the elastically deformable element 54 are arranged within an actuator housing 60. The actuator housing 60 is attached to the mesh element housing 52 to define a cavity 62 between the mesh element 10 and the elastically deformable element 54. The actuator housing 60 defines a liquid inlet 64 for providing a supply of liquid to be atomised to the cavity 62.

[0132] During use, liquid to be atomised is supplied to the cavity 62 through the liquid inlet 64. The actuator 56 oscillates the elastically deformable element 54 to force at least some of the liquid within the cavity 62 through the channels 14 and the nozzles 18 of the mesh element 10. The liquid forced through the nozzles 18 of the mesh element 10 form droplets. The momentum of the liquid forced through the nozzles 18 to form the droplets carries the droplets away from the mesh element 10. Therefore, during use, the atomiser assembly 50 generates an aerosol comprising liquid droplets ejected through the mesh element 10.

[0133] FIG. 7 shows a cross-sectional view of an aerosol-generating system 70 according to an embodiment of the present invention. The aerosol-generating system 70 comprises an aerosol-generating device 72 and a liquid reservoir 74.

[0134] The aerosol-generating device 72 comprises a housing 76 comprising a first housing portion 78 and a second housing portion 80. A controller 82 and a power supply 84 comprising a battery are positioned within the first housing portion 78. A mouthpiece 85 defining a mouthpiece channel 87 is connectable to the second housing portion 80.

[0135] The second housing portion 80 defines a liquid reservoir chamber 86 for receiving the liquid reservoir 74. The first housing portion 78 is detachable from the second housing portion 80 to allow replacement of the liquid reservoir 74.

[0136] The aerosol-generating device 72 also comprises a device connector 88 positioned within the liquid reservoir chamber 86 for engagement with a reservoir connector 90 that forms part of the liquid reservoir 74.

[0137] The aerosol-generating device 72 comprises the atomiser assembly 50 of FIG. 6 positioned within the second housing portion 80. The liquid inlet 64 of the atomiser assembly 50 is in fluid communication with the device connector 88. The mesh element 10 of the atomiser assembly 50 is positioned within an aerosol chamber 92 defined by the second housing portion 80.

[0138] The liquid reservoir 74 comprises a container 94 and a liquid aerosol-forming substrate 96 positioned within the container 94. When the reservoir connector 90 is engaged with the device connector 88, liquid aerosol-forming substrate 96 from the liquid reservoir 74 is supplied to the cavity 62 of the atomiser assembly 50 through the reservoir connector 90, the device connector 88, and the liquid inlet 64 of the atomiser assembly 50.

[0139] When the first housing portion 78 is connected to the second housing portion 80, the controller 82 controls a supply of power from the power supply 84 to the actuator 56 to eject droplets of the liquid aerosol-forming substrate 96 into the aerosol chamber 92 from the mesh element 10.

[0140] The second housing portion 80 defines an air inlet 98 and an air outlet 100 each in fluid communication with the aerosol chamber 92. During use, a user draws on the mouthpiece 85 to draw air into the aerosol chamber 92 through the air inlet 98. The air flows through the aerosol chamber 92 where droplets of liquid aerosol-forming substrate 96 ejected from the mesh element 10 are entrained within the airflow to form an aerosol. The aerosol flows out of the aerosol chamber 92 through the air outlet 100 and is delivered to the user through the mouthpiece channel 87.

[0141] The aerosol-generating device 72 also comprises an airflow sensor 102 positioned within the aerosol chamber 92. The airflow sensor 102 is arranged to provide a signal to the controller 82 indicative of a user drawing on the mouthpiece 85. The controller 82 is arranged to supply power from the power supply 84 to the actuator 56 of the atomiser assembly 50 only when the controller receives a signal from the airflow sensor 102 indicative of a user drawing on the mouthpiece 85.