Electronic smoking article comprising one or more microheaters
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.
1. An aerosol forming article comprising:
an electrical power source;
an atomizing chamber defined by a plurality of walls, the atomizing chamber including at least one entry adapted for passage of aliquots of an aerosol precursor composition into the chamber and at least one exit adapted for passage therefrom of vapor formed within the atomizing chamber;
a controller adapted to control active flow of the aliquots of the aerosol precursor composition into the atomizing chamber;
a microheater that forms at least a portion of one of the plurality of walls defining the atomizing chamber, the microheater comprising an electrically conductive material overlying a supporting layer and being configured to vaporize the aliquots of the aerosol precursor composition and form a vapor within the atomizing chamber; and
an airflow passage passing at least partially around the atomizing chamber;
wherein the at least one exit of the atomizing chamber is in fluid communication with the airflow passage passing at least partially around the atomizing chamber such that the vapor formed within the atomizing chamber passes from the at least one exit of the atomizing chamber into the airflow passage to mix with air in the airflow passage and form an aerosol.
2. The aerosol forming article according to claim 1 , wherein the electrically conductive material is selected from the group consisting of elemental metals, metal alloys, silicon, ceramics, carbon, carbides, nitrides, and combinations thereof.
3. The aerosol forming article according to claim 1 , wherein the electrically conductive material is a printed layer overlying the supporting layer.
4. The aerosol forming article according to claim 1 , wherein the supporting layer comprises a silicon-based material.
5. The aerosol forming article according to claim 1 , wherein the microheater comprises a protective layer overlying the electrically conductive material.
6. The aerosol forming article according to claim 1 , comprising a plurality of microheaters.
7. The aerosol forming article according to claim 1 , wherein the electrical power source, the atomizing chamber, the controller, and the microheater are positioned within a shell.
8. The aerosol forming article according to claim 1 , wherein the electrical power source and the controller are positioned within a shell, and the atomizing chamber and the microheater are positioned within a separate shell.
9. A method of forming an aerosol comprising:
providing an aerosol forming article according to claim 1 ;
initiating active flow of the aliquots of the aerosol precursor composition into the atomizing chamber; and
initiating current flow from the electrical power source to the microheater so as to cause heating of the microheater and the aliquots of the aerosol precursor composition within the atomizing chamber.
10. The aerosol forming article of claim 1 , wherein the microheater is configured to vaporize the aliquots of the aerosol precursor composition by heating to a temperature of about 120° C. or greater.
11. The aerosol forming article of claim 1 , wherein the microheater is configured to vaporize the aliquots of the aerosol precursor composition by heating to a temperature of about 120° C. to about 350° C.
12. The aerosol forming article of claim 1 , wherein the atomizing chamber includes at least one opening adapted for infiltration of air into the atomizing chamber.