EP-4736681-A2 - MICROTEXTURED LIQUID TRANSPORT ELEMENT FOR AEROSOL DELIVERY DEVICE

Abstract

The present disclosure relates to aerosol delivery devices. The aerosol delivery devices may include a reservoir containing a liquid aerosol precursor composition and an atomizer including an electrical resistance heating element and a nonfibrous liquid transport element having a microtextured surface adapted for surface wicking of the liquid aerosol precursor composition across the microtextured surface, the microtextured surface of the liquid transport element being in fluid communication with the reservoir and in fluid communication with the electric resistance heating element.

Inventors

• DAVIS, MICHAEL F.
• AMPOLINI, Frederic Philippe
• ROGERS, JAMES WILLIAM
• SEBASTIAN, ANDRIES DON
• HUNT, ERIC TAYLOR
• HUBBARD, SAWYER
• BRAMMER, DAVID ALLAN

Assignees

• RAI Strategic Holdings, Inc.

Dates

Publication Date

20260506

Application Date

20180816

Claims (15)

1. An aerosol delivery device, comprising: a reservoir containing a liquid aerosol precursor composition; and an atomizer comprising: a nonfibrous liquid transport element in fluid communication with the reservoir, the nonfibrous liquid transport element having a microtextured surface; and an electrical resistance heating element in the form of a pattern on the microtextured surface of the nonfibrous liquid transport element.
2. The aerosol delivery device of claim 1, wherein the microtextured surface of the nonfibrous liquid transport element is adapted for surface wicking of the liquid aerosol precursor composition.
3. The aerosol delivery device of claim 1, wherein the microtextured surface of the nonfibrous liquid transport element exhibits topographical three-dimensional features at the micro-meter scale.
4. The aerosol delivery device of claim 3, wherein the topographical three-dimensional features are discontinuous in appearance such that the surface includes multiple concave and convex portions, optionally wherein the topographical three-dimensional features are patterned as an ordered array of structures, and optionally wherein the topographical three-dimensional features are randomly arranged.
5. The aerosol delivery device of claim 1, wherein the microtextured surface of the nonfibrous liquid transport element exhibits a relatively non-uniform plurality of surface protrusions, or wherein the microtextured surface of the nonfibrous liquid transport element exhibits an irregular plurality of surface protrusions, and optionally wherein the microtextured surface of the nonfibrous liquid transport element is adapted to provide surface wicking across the surface such that a steady supply of the liquid aerosol precursor composition is delivered directly into close proximity of the heating element.
6. The aerosol delivery device of claim 1, wherein the nonfibrous liquid transport element comprises a ceramic material, and optionally wherein the nonfibrous liquid transport element has a surface area of about 0.5 cm 2 to about 50 cm 2 .
7. The aerosol delivery device of claim 1, wherein the electrical resistance heating element is physically combined with the microtextured surface of the nonfibrous liquid transport element.
8. The aerosol delivery device of claim 7, wherein the electrical resistance heating element is combined with the microtextured surface of the nonfibrous liquid transport element by etching so as to be present as an etched electrical resistance heating element, optionally wherein the electrical resistance heating element is combined with the microtextured surface of the nonfibrous liquid transport element by printing so as to be present as a printed electrical resistance heating element, or optionally wherein the electrical resistance heating element is adhered to the microtextured surface of the nonfibrous liquid transport element.
9. The aerosol delivery device of claim 1, wherein the electrical resistance heating element is in the form of a film patterned on the microtextured surface of the nonfibrous liquid transport element, optionally wherein the film patterned on the microtextured surface has a thickness of about 1,000 µm or less, and optionally wherein the film patterned on the microtextured surface has a thickness of about 0.1 µm to about 500 µm.
10. The aerosol delivery device of claim 1, wherein the electrical resistance heating element comprises one or more of: an electrically conductive material selected from the group consisting of elemental metals, metal alloys, silicon, ceramics, carbon, carbides, nitrides, and combinations thereof; and a conductive ink.
11. The aerosol delivery device of claim 1, wherein the pattern on the microtextured surface of the nonfibrous liquid transport element is curvilinear and extends from a first end to a second end.
12. The aerosol delivery device of claim 1, wherein the nonfibrous liquid transport element comprises one or more grooves or notches.
13. The aerosol delivery device of claim 1, wherein the microtextured surface of the nonfibrous liquid transport element on which the electrical resistance heating element is present in the form of a pattern is substantially planar, and optionally wherein the substantially planar microtextured surface is substantially perpendicular to a longitudinal axis of the aerosol delivery device.
14. The aerosol delivery device of claim 1, further comprising a positive electric terminal and a negative electric terminal, and optionally wherein the reservoir and atomizer are housed in a cartridge adapted for attachment to a control body, the control body comprising an electrical power source configured to provide electrical current flow to the electrical resistance heating element.
15. The aerosol delivery device of claim 1, further comprising one or more of: (a) an electrical power source configured to provide electrical current flow to the electrical resistance heating element; (b) a controller adapted for controlling electrical current flow from the electrical power source; and (c) a flow sensor adapted to sense a pressure drop within the aerosol delivery device or a portion thereof.

Description

BACKGROUND Field of the Disclosure The present disclosure relates to aerosol delivery devices such as electronic cigarettes, and more particularly to aerosol delivery devices including an atomizer. The atomizer may be configured to heat an aerosol precursor composition, which may be made or derived from tobacco or otherwise incorporate tobacco, to form an inhalable substance for human consumption. Description of Related Art Many devices have been proposed through the years as improvements upon, or alternatives to, smoking products that require combusting tobacco for use. Many of those devices purportedly have been designed to provide the sensations associated with cigarette, cigar, or pipe smoking, but without delivering considerable quantities of incomplete combustion and pyrolysis products that result from the burning of tobacco. To this end, there have been proposed numerous alternative smoking products, flavor generators, and medicinal inhalers that utilize electrical energy to vaporize or heat a volatile material, or attempt to provide the sensations of cigarette, cigar, or pipe smoking without burning tobacco to a significant degree. See, for example, the various alternative smoking articles, aerosol delivery devices and heat generating sources set forth in the background art described in U.S. Pat. No. 8,881,737 to Collett et al., U.S. Pat. App. Pub. No. 2013/0255702 to Griffith Jr. et al., U.S. Pat. App. Pub. No. 2014/0000638 to Sebastian et al., U.S. Pat. App. Pub. No. 2014/0096781 to Sears et al., U.S. Pat. App. Pub. No. 2014/0096782 to Ampolini et al., and U.S. Pat. App. Pub. No. 2015/0059780 to Davis et al., which are incorporated herein by reference in their entireties. See also, for example, the various embodiments of products and heating configurations described in the background sections of U.S. Pat. Nos. 5,388,594 to Counts et al. and 8,079,371 to Robinson et al., which are incorporated by reference in their entireties. Many electronic cigarette products comprise an atomizer with a "wick/coil" design, which includes an electrical resistance heater wire wrapped around a fibrous wicking material. Such a design has several potential drawbacks, including heating inefficiency, non-homogeneous wicking of liquid components, non-uniform heating or vaporization of liquid components, the presence of heat sinks, and non-optimal aerodynamics. In addition, the wick/coil design may lead to pyrolysis and/or deposition of char at the wick and coil interface. Some of these potential drawbacks can cause a negative sensory impact over time that may limit how long the device can be operated before the atomizer needs replacement. There remains a need in the art for new atomizer configurations that can improve upon one or more characteristics of an aerosol delivery device, such as uniformity of heating or vaporization, heating efficiency, reduction of charring/pyrolysis, and the like. BRIEF SUMMARY OF THE DISCLOSURE The present disclosure relates to an atomizer for aerosol delivery devices configured to produce aerosol and which aerosol delivery devices, in some embodiments, may be referred to as electronic cigarettes. In one aspect, an aerosol delivery device is provided that includes a reservoir containing a liquid aerosol precursor composition and an atomizer comprising an electrical resistance heating element and a nonfibrous liquid transport element (which is optionally plate-shaped) having a microtextured surface adapted for surface wicking of the liquid aerosol precursor composition across the microtextured surface, the microtextured surface of the liquid transport element being in fluid communication with the reservoir and in fluid communication with the electric resistance heating element. Use of a microtextured solid surface enables surface wicking of the aerosol precursor composition from a first portion of the liquid transport element into a heating zone proximal to the heating element. In certain embodiments, the electrical resistance heating element is a film (e.g., a conductive ink) patterned on the microtextured surface of the nonfibrous liquid transport element. The film patterned on the microtextured surface can include one or more straight or curvilinear elements extending from a first end to a second end. A protective layer overlying the electrical resistance heating element can also be included such that liquid aerosol precursor composition transported across the microtextured surface does not directly contact the electrical resistance heating element. In certain embodiments, the film patterned on the microtextured surface extends from a first end to a second end, and the device further comprises an aperture in the nonfibrous liquid transport element proximal to each of the first end and the second end, and further comprises a positive electric terminal engaged with a first end of the film through an aperture and a negative electric terminal engaged with a second end of the film through an ap