AEROSOL GENERATOR COMPRISING A SURFACE ACOUSTIC WAVE ATOMISER

Abstract

An aerosol-generator for an aerosol-generating device is provided, the aerosol-generator including: a surface acoustic wave atomiser including a substrate including an active surface defining an atomisation region, and a transducer disposed on the active surface of the substrate; a supply element arranged to supply a liquid aerosol-forming substrate to the atomisation region; and a controller configured to operate the transducer as an input transducer to generate surface acoustic waves on the active surface of the substrate, operate the transducer as an output transducer to sense surface acoustic waves on the active surface of the substrate, and receive an output signal from the transducer when the transducer is operated as the output transducer. An aerosol-generating device including the aerosol-generator is also provided.

Claims

1.-15. (canceled)

16. An aerosol-generator for an aerosol-generating device, the aerosol-generator comprising: a surface acoustic wave atomiser comprising: a substrate comprising an active surface defining an atomisation region, and a transducer disposed on the active surface of the substrate; a supply element arranged to supply a liquid aerosol-forming substrate to the atomisation region; and a controller configured to: operate the transducer as an input transducer to generate surface acoustic waves on the active surface of the substrate, operate the transducer as an output transducer to sense surface acoustic waves on the active surface of the substrate, and receive an output signal from the transducer when the transducer is operated as the output transducer.

17. The aerosol-generator according to claim 16, wherein the controller is further configured to: provide an input signal to the transducer when the transducer is operated as an input transducer, and vary the input signal to control the input transducer based on the output signal received by the controller from the transducer when the transducer is operated as an output transducer.

18. The aerosol-generator according to claim 16, further comprising a flow control element configured to control a flow rate of liquid aerosol-forming substrate supplied to the atomisation region by the supply element, wherein the controller is further configured to: provide an input signal to the flow control element, and vary the input signal based on the output signal received by the controller from the transducer when the transducer is operated as the output transducer.

19. The aerosol-generator according to claim 16, further comprising a reflector disposed on the active surface of the substrate, wherein the atomisation region is disposed between the transducer and the reflector.

20. The aerosol-generator according to claim 19, wherein the transducer is a first transducer, wherein the reflector is a first reflector, wherein the surface acoustic wave atomiser further comprises: a second transducer disposed on the active surface of the substrate, wherein the controller is further configured to operate the second transducer as an input transducer to generate surface acoustic waves on the active surface of the substrate, and to operate the second transducer as an output transducer to sense surface acoustic waves, and a second reflector positioned to reflect the surface acoustic waves generated by the second transducer when operated as an input transducer, such that the reflected surface acoustic waves are received by the second transducer when operated as the output transducer, wherein the controller is further configured to receive an output signal from the second transducer when the second transducer is operated as an output transducer, and wherein the atomisation region is disposed only between the first transducer and the first reflector.

21. An aerosol-generator for an aerosol-generating device, the aerosol-generator comprising: a surface acoustic wave atomiser comprising: a substrate comprising an active surface defining an atomisation region, and a first transducer, a second transducer, a third transducer, and a fourth transducer, each disposed on the active surface of the substrate; a supply element arranged to supply a liquid aerosol-forming substrate to the atomisation region; and a controller configured to: operate the first transducer, the second transducer, the third transducer, and the fourth transducer, and operate each of the first transducer and the second transducer as an input transducer to generate surface acoustic waves on the active surface of the substrate, wherein the third transducer is positioned to receive surface acoustic waves generated by the first transducer, and wherein the controller is further configured to operate the third transducer as an output transducer to sense surface acoustic waves generated by the first transducer, and to receive an output signal from the third transducer, wherein the fourth transducer is positioned to receive surface acoustic waves generated by the second transducer, and wherein the controller is further configured to operate the fourth transducer as an output transducer to sense surface acoustic waves generated by the second transducer, and to receive an output signal from the fourth transducer, and wherein the atomisation region is disposed only between the first transducer and the third transducer.

22. The aerosol-generator according to claim 21, wherein the controller is further configured to: provide a first input signal to the first transducer and a second input signal to the second transducer, and vary the first input signal to control the first input transducer and the second input signal to control the second input transducer based on a comparison between the output signal received by the controller from the third transducer and the output signal received by the controller from the fourth transducer.

23. The aerosol-generator according to claim 22, wherein the second input signal is identical to the first input signal.

24. The aerosol-generator according to claim 22, wherein the supply element comprises a flow control element arranged to control a flow rate of liquid aerosol-forming substrate supplied to the atomisation region by the supply element, and wherein the controller is further configured to: provide an input signal to the flow control element, and vary the input signal based on a comparison between the output signal received by the controller from the third transducer and the output signal received by the controller from the fourth transducer.

25. An aerosol-generator for an aerosol-generating device, the aerosol-generator comprising: a surface acoustic wave atomiser comprising: a substrate comprising an active surface defining an atomisation region, a first transducer disposed on the active surface of the substrate, and a second transducer disposed on the active surface of the substrate, wherein the atomisation region is disposed between the first transducer and the second transducer; a supply element arranged to supply a liquid aerosol-forming substrate to the atomisation region; a controller configured to: operate the first transducer as an input transducer to generate surface acoustic waves on the active surface of the substrate, the second transducer being positioned to receive surface acoustic waves generated by the first transducer, and operate the second transducer as an output transducer to sense surface acoustic waves generated by the first transducer, such that the second transducer provides an output signal; an amplifier, wherein the surface acoustic wave atomiser is arranged as a feedback line for the amplifier, such that the amplifier is configured to receive the output signal for the second transducer and to provide an amplifier output signal; and an analyser configured to receive the amplifier output signal and provide an analyser output signal to the controller.

26. The aerosol-generator according to claim 25, wherein the analyser comprises at least one of a frequency analyser, a power analyser, and a phase analyser.

27. The aerosol-generator according to claim 25, wherein the controller is further configured to: provide an input signal to the first transducer, and vary the input signal to control the first transducer based on the analyser output signal received by the controller.

28. The aerosol-generator according to claim 25, wherein the supply element comprises a flow control element arranged to control a flow rate of liquid aerosol-forming substrate supplied to the atomisation region by the supply element, and wherein the controller is further configured to: provide an input signal to the flow control element, and vary the input signal based on the analyser output signal received by the controller.

29. The aerosol-generator according to claim 16, wherein the substrate is a piezoelectric substrate.

30. The aerosol-generator according to claim 21, wherein the substrate is a piezoelectric substrate.

31. The aerosol-generator according to claim 25, wherein the substrate is a piezoelectric substrate.

32. An aerosol-generating device, comprising: an aerosol-generator according to claim 16; a power supply; and a liquid storage portion configured to receive a liquid aerosol-forming substrate, wherein the supply element is arranged to supply liquid aerosol-forming substrate from the liquid storage portion to the atomisation region.

33. An aerosol-generating device, comprising: an aerosol-generator according to claim 21; a power supply; and a liquid storage portion configured to receive a liquid aerosol-forming substrate, wherein the supply element is arranged to supply liquid aerosol-forming substrate from the liquid storage portion to the atomisation region.

34. An aerosol-generating device, comprising: an aerosol-generator according to claim 25; a power supply; and a liquid storage portion configured to receive a liquid aerosol-forming substrate, wherein the supply element is arranged to supply liquid aerosol-forming substrate from the liquid storage portion to the atomisation region.

Description

[0113] These and other features and advantages of the invention will become more evident in the light of the following detailed description of preferred embodiments, given only by way of illustrative and non-limiting example, in reference to the attached figures:

[0114] FIG. 1 shows a top view of an aerosol generator comprising a transducer and a reflector.

[0115] FIG. 2 illustrates a top view of an aerosol generator comprising a transducer and a reflector, wherein the reflector is comprised in a plurality of walls forming a recess.

[0116] FIG. 3 depicts a perspective view of the aerosol generator of FIG. 2.

[0117] FIG. 4 represents an aerosol generator identical to that of FIG. 1 except in that it does not comprise a reflector.

[0118] FIG. 5 illustrates a top view of an aerosol generator comprising a first transducer, a second transducer, a first reflector and a second reflector.

[0119] FIG. 6 depicts a top view of an aerosol generator comprising a first transducer, a second transducer, a third transducer and a fourth transducer.

[0120] FIG. 7 shows a top view of an aerosol generator comprising a first transducer, a second transducer, an amplifier and an analyser.

[0121] FIG. 8 represents an aerosol-generating device comprising an aerosol generator.

[0122] The aerosol generator 100 of the embodiment of FIG. 1 comprises a controller 101, a surface acoustic wave atomiser 102, a flow control element 103 and a supply element 104.

[0123] The surface acoustic wave atomiser 102 comprises a substrate 106 comprising a sheet of piezoelectric material, and a transducer 108 arranged on an active surface 110 of the substrate 106. The transducer 108 comprises a first array of electrodes 112 and a second array of electrodes 114 interleaved with the first array of electrodes 112. The first and second arrays of electrodes 112, 114 are linear and parallel with each other. During use, the transducer 108 generates surface acoustic waves on the active surface 110 of the substrate 106. The linear shape of the first and second arrays of electrodes 112, 114 results in surface acoustic waves having a linear wavefront directed towards an atomisation region 116 on the active surface 110 of the substrate 106.

[0124] The controller 101 is configured to operate the transducer 108. For this reason, the controller 101 is electrically connected to the transducer 108. The controller 101 is configured to operate the transducer 108 as an input transducer for generating surface acoustic waves on the active surface 110 of the substrate 106. The controller 101 is also configured to operate the transducer 108 as an output transducer for sensing surface acoustic waves on the active surface 110 of the substrate 106.

[0125] The supply element 104 comprises a channel extending through the substrate 106 between an inlet at a passive surface of the substrate (not represented) and an outlet 105 at the active surface 110 of the substrate 106. The outlet 105 is positioned within the atomisation region 116. During use, a liquid aerosol-forming substrate is supplied through the channel to the atomisation region 116 where it is atomised by surface acoustic waves generated by the transducer 108.

[0126] The aerosol generator 100 also comprises a reflector 130 positioned on the active surface 110 of the substrate 106 so that the atomisation region 116 is positioned between the transducer 108 and the reflector 130. The reflector 130 comprises an array of reflector electrodes 132, each having a linear shape and arranged parallel with each other and the first and second arrays 112, 114 of electrodes of the transducer 108. During use, some of the surface acoustic waves generated by the transducer 108 may be transmitted entirely through the atomisation region 116, for example if a small amount of liquid aerosol-forming substrate, or no liquid aerosol-forming substrate, is deposited on the atomisation region 116. The reflector 130 functions to reflect any transmitted surface acoustic waves back towards the atomisation region 116 and towards the transducer 108. When the reflected surface acoustic waves reach the transducer 108, the controller 101 operates the transducer 108 as an output transducer for sensing the reflected surface acoustic waves.

[0127] Since the transducer 108 can be operated as an input transducer and an output transducer, the transducer 108 forms a sensor which can sense a sample of the liquid aerosol-forming substrate on the atomisation region 116. When the transducer 108 is operated as an output transducer, it generates an output signal which is a function of the properties of the sensed liquid aerosol-forming substrate. The output signal is received by the controller 101, which can modify an input signal sent to the transducer 108 when the transducer 108 is operated as an input transducer. As a result of this, the transducer 108 operating as an input transducer adapts the generation of surface acoustic waves to enhance the atomisation of the liquid aerosol-forming substrate.

[0128] When the output signal is received by the controller 101, the controller 101 provides an input signal to the flow control element 103. The flow control element 103 adapts a flow rate of the liquid aerosol-forming substrate to the atomisation region 116 on the active surface 110 of the substrate 106, by means of the supply element 104, to enhance the atomisation of liquid aerosol-forming substrate.

[0129] FIGS. 2 and 3 show an aerosol generator similar to that of FIG. 1, except in that the reflector 130 is comprised in a plurality of walls 142 defining a recess 140. The plurality of walls 142 comprises a pair of angled walls 144 arranged to reflect surface acoustic waves generated by the transducer 108 towards the atomisation region 116. The plurality of walls 142 also comprises a back wall 146 arranged to reflect any surface acoustic waves propagating from the transducer 108 in a direction away from the atomisation region 116 back towards the atomisation region 116 and towards the transducer 108. When the reflected surface acoustic waves reach the transducer 108, the controller 101 operates the transducer as an output transducer for sensing the reflected surface acoustic waves. The controller 101 can control the transducer 108, when operated as an input transducer, and the flow control element 103 as in the embodiment of FIG. 1.

[0130] The embodiment of FIG. 4 is identical to that of FIGS. 1 to 3 except in that no reflector is provided. Hence, only the surface acoustic waves that reach the liquid aerosol-forming substrate in the atomisation region 116 are reflected by the liquid aerosol-forming substrate towards the transducer 108. When the reflected surface acoustic waves reach the transducer 108, the controller 110 operates the transducer as an output transducer for sensing the reflected surface acoustic waves. The controller can control the transducer 108, when operated as an input transducer, and the flow control element 103 as in the embodiments of FIGS. 1 to 3.

[0131] In the embodiment of FIG. 5, a surface acoustic wave atomiser 102 of an aerosol generator 100 comprises a substrate 106 in turn comprising a sheet of piezoelectric material, a first transducer 108, a second transducer 109, a third transducer 111 and a fourth transducer 113. The first 108, second 109, third 111 and fourth 113 transducers are arranged on an active surface 110 of the substrate 106.

[0132] Each of the transducers 108, 109, 111, 113 comprises a first array of electrodes 112 and a second array of electrodes 114 interleaved with the first array of electrodes 112. The first and second arrays of electrodes of each of the transducers 108, 109, 111, 113 are curved and parallel with each other.

[0133] A controller 101 is configured to operate each of the first transducer 108 and the second transducer 109 as an input transducer for generating surface acoustic waves on the active surface 110 of the substrate 106. The third transducer 111 is positioned to receive surface acoustic waves generated by the first transducer 108, and the controller 101 is configured to operate the third transducer 111 as an output transducer for sensing surface acoustic waves generated by the first transducer 108. Likewise, the fourth transducer 113 is positioned to receive surface acoustic waves generated by the second transducer 109, and the controller 101 is configured to operate the fourth transducer 113 as an output transducer for sensing surface acoustic waves generated by the second transducer 109.

[0134] During use, each of the first 108 and second 109 transducers generates surface acoustic waves on the active surface 110 of the substrate 106. The curved shape of the first 112 and second 114 arrays of electrodes of the first transducer 108 results in surface acoustic waves having a concave wavefront focussed towards the atomisation region 116 on the active surface 110 of the substrate 106 and towards the third transducer 111. The curved shape of the first 112 and second 114 arrays of electrodes of the second transducer 109 results in surface acoustic waves having a concave wavefront focussed towards the fourth transducer 113.

[0135] The atomisation region 116 is positioned only between the first transducer 108 and the third transducer 111. Hence, the second transducer 109 and the fourth transducer 113 may be configured to form a reference sensor, whereas the first transducer 108 and the third transducer 111 may form a sensor configured to sense the liquid aerosol-forming substrate within the atomisation region 116.

[0136] The second transducer 111 generates an output signal which is a function of the properties of the sensed liquid aerosol-forming substrate. Likewise, the fourth transducer 113 generates an output signal which is independent from the properties of the liquid aerosol-forming substrate in the atomisation region 116. The output signal of the fourth transducer 113 can thus be used as a reference output signal. The output signals from the third 111 and fourth 113 transducers are received by the controller 101, which can thus compare the output signal of the third transducer 111 to the reference output signal of the fourth transducer 113.

[0137] As a result of this comparison, the controller 101 can modify the input signal sent to the first transducer 108, which adapts the generation of surface acoustic waves to enhance the atomisation of the liquid aerosol-forming substrate.

[0138] The controller 101 of FIG. 5 also utilises the comparison between the output signal of the third transducer 111 and the reference output signal of the fourth transducer 113 to provide an input signal to a flow control element 103. The flow control element 103 adapts the flow rate of the liquid aerosol-forming substrate to the atomisation region 116 on the active surface 110 of the substrate 106, by means of a supply element 104, to enhance the atomisation of liquid aerosol-forming substrate.

[0139] The controller 101 can be configured to control the first 108 and second 109 transducers in such a way that they generate identical surface acoustic waves. This may be beneficial to ensure that the comparison between the output signal of the third transducer 111 and the reference output signal of the fourth transducer 113 is consistent.

[0140] In the embodiment of FIG. 6, a surface acoustic wave atomiser 102 of an aerosol generator 100 comprises a substrate 106 in turn comprising a sheet of piezoelectric material, a first transducer 108 and a second transducer 109. The aerosol generator 100 also comprises a first reflector 130 and a second reflector 134. The first transducer 108, second transducer 109, first reflector 130 and second reflector 134 are arranged on an active surface 110 of the substrate 106.

[0141] Each of the transducers 108, 109 comprises a first array of electrodes 112 and a second array of electrodes 114 interleaved with the first array of electrodes 112. The first and second arrays of electrodes of each of the transducers 108, 109 are curved and parallel with each other.

[0142] A controller 101 is configured to operate the first transducer 108 and the second transducer 109. For this reason, the controller 101 is electrically connected to the first transducer 108 and the second transducer 109. The controller 101 is configured to operate the first transducer 108 and the second transducer 109 as input transducers for generating surface acoustic waves on the active surface 110 of the substrate 106. The controller 101 is also configured to operate the first transducer 108 and the second transducer 109 as output transducers for sensing surface acoustic waves on the active surface 110 of the substrate 106.

[0143] The aerosol generator 100 comprises a first reflector 130 positioned on the active surface 110 of the substrate 106 so that the atomisation region 116 is positioned only between the transducer 108 and the first reflector 130. The first reflector 130 comprises an array of reflector electrodes 132 each having a linear shape and arranged parallel with each other.

[0144] The aerosol generator 100 also comprises a second reflector 134 positioned on the active surface 110 of the substrate 106. The second reflector 134 also comprises an array of reflector electrodes 132 each having a linear shape and arranged parallel with each other.

[0145] Since the atomisation region 116 is positioned only between the first transducer 108 and the first reflector 130, the second transducer 109 may be configured to form a reference sensor, whereas the first transducer 108 may form a sensor configured to sense the liquid aerosol-forming substrate within the atomisation region 116.

[0146] During use, some of the surface acoustic waves generated by the first transducer 108 may be transmitted entirely through the atomisation region 116, for example if a small amount of liquid aerosol-forming substrate, or no liquid aerosol-forming substrate, is deposited on the atomisation region 116. The first reflector 130 functions to reflect any transmitted surface acoustic waves back towards the atomisation region 116 and towards the first transducer 108. When the reflected surface acoustic waves reach the first transducer 108, the controller 101 operates the first transducer 108 as an output transducer for sensing the reflected surface acoustic waves.

[0147] Likewise, during use, the surface acoustic waves generated by the second transducer 109 reach the second reflector 134, which reflects any transmitted surface acoustic waves back towards the second transducer 109. When the reflected surface acoustic waves reach the second transducer 109, the controller 101 operates the second transducer 109 as an output transducer for sensing the reflected surface acoustic waves.

[0148] Since the first transducer 108 can be operated as an input transducer and an output transducer, the first transducer 108 forms a sensor which can sense a sample of the liquid aerosol-forming substrate on the atomisation region 116. When the first transducer 108 is operated as an output transducer, it generates an output signal which is a function of the properties of the sensed liquid aerosol-forming substrate.

[0149] Similarly, the second transducer 111, when operated as an output transducer, generates an output signal which is independent from the properties of the liquid aerosol-forming substrate in the atomisation region 116. The output signal of the second transducer 109 can thus be used as a reference output signal. The output signals from the first 108 and second 109 transducers are received by the controller 101, which can thus compare the output signal of the first transducer 108 to the reference output signal of the second transducer 109.

[0150] As a result of this comparison, the controller 101 can modify the input signal sent to the first transducer 108 when operated as an input transducer. The first transducer 108 can therefore adapt the generation of surface acoustic waves to enhance the atomisation of the liquid aerosol-forming substrate.

[0151] The controller 101 of FIG. 6 may also use the comparison between the output signal of the first transducer 108 and the reference output signal of the second transducer 109 to provide an input signal to a flow control element 103. The flow control element 103 adapts the flow rate of the liquid aerosol-forming substrate to the atomisation region 116 on the active surface 110 of the substrate 106, by means of a supply element 104, to enhance the atomisation of liquid aerosol-forming substrate.

[0152] The controller 101 can be configured to control the first 108 and second 109 transducer in such a way that they generate identical surface acoustic waves when operated as input transducers. This may be beneficial to ensure that the comparison between the output signal of the first transducer 108 and the reference output signal of the second transducer 109, when operated as output transducers, is consistent.

[0153] In the embodiment of FIG. 7, a surface acoustic wave atomiser 102 of an aerosol generator 100 comprises a substrate 106 in turn comprising a sheet of piezoelectric material, a first transducer 108 and a second transducer 109. The first 108 and second 109 transducers are arranged on an active surface 110 of the substrate 106.

[0154] Each of the transducers 108, 109 comprises a first array of electrodes 112 and a second array of electrodes 114 interleaved with the first array of electrodes 112. The first 112 and second 114 arrays of electrodes of each of the first 108 and second 109 transducers are curved and parallel with each other.

[0155] The controller 101 is configured to operate the first transducer 108 as an input transducer for generating surface acoustic waves on the active surface 110 of the substrate 106. The second transducer 109 is positioned to receive surface acoustic waves generated by the first transducer 108, and the controller 101 is configured to operate the second transducer 109 as an output transducer for sensing surface acoustic waves generated by the first transducer 108.

[0156] During use, the first transducer 108 generates surface acoustic waves on the active surface 110 of the substrate 106. The curved shape of the first 112 and second 114 arrays of electrodes of the first transducer 108 results in surface acoustic waves having a concave wavefront focussed towards an atomisation region 116 on the active surface 110 of the substrate 106 and towards the second transducer 109.

[0157] The aerosol generator 100 of FIG. 7 comprises an amplifier 115, such that the first transducer 108 and the second transducer 109 are arranged in such a way that the acoustic wave atomiser 102 is a feedback line for the amplifier 115, as shown in FIG. 6. In particular, in the embodiment of FIG. 7, the second transducer 109 generates an output signal which is a function of the properties of the sensed liquid aerosol-forming substrate. The output signal of the second transducer 109 is amplified by the amplifier 115, which generates an amplifier output signal. The amplifier output signal is received by an analyser 117 which in turns provides an analyser output signal to the controller 101.

[0158] The controller 101 can utilise the analyser output signal to modify an input signal sent to the first transducer 108, which adapts the generation of surface acoustic waves to enhance the atomisation of the liquid aerosol-forming substrate.

[0159] The controller 101 of FIG. 7 can also use the analyser output signal to provide an input signal to a flow control element 103. The flow control element 103 adapts the flow rate of the liquid aerosol-forming substrate to the atomisation region 116 on the active surface 110 of the substrate 106, by means of a supply element 104, to enhance the atomisation of liquid aerosol-forming substrate.

[0160] FIG. 8 shows a cross-sectional view of an aerosol-generating device 600 comprising the aerosol generator 100 of any of the embodiments above. The aerosol-generating device 600 also comprises a liquid storage portion 602 containing a liquid aerosol-forming substrate 604. The flow control element 103 of the aerosol generator 100 controls the flow rate of the liquid aerosol-forming substrate 604, by means of the supply element 104, to the atomisation region 116. The supply element 104 comprises a channel 118 and an outlet 105.

[0161] The aerosol-generating device 600 also comprises a power supply 608 comprising a rechargeable battery, electrically connected to the controller 101. As explained for the embodiments above, the controller 101 is configured to provide input signals to the flow control element 103 and to the one or more input transducers of the aerosol generator 100.

[0162] The aerosol-generating device 600 also comprises a housing 612 in which the aerosol generator 100, the liquid storage portion 602 and the power supply 608 are contained. The housing 612 defines an air inlet 614, a mouthpiece 616, and an air outlet 618. During use, a user draws on the mouthpiece 616 to draw air through the housing 612 from the air inlet 614 to the air outlet 618. Aerosol generated by the aerosol generator 100 is entrained in the airflow through the housing 612 for delivery to the user.