Heater assembly for an aerosol-generating system

1. A heater assembly for an aerosol-generating system having a liquid storage portion configured to hold a liquid aerosol-forming substrate, the heater assembly comprising:

an electric heater having at least one heating element configured to heat the liquid aerosol-forming substrate to form an aerosol; and

an elongate capillary body configured to convey the liquid aerosol-forming substrate from the liquid storage portion of the aerosol-generating system to the at least one heating element,

wherein the at least one heating element is formed from an electrically conductive material deposited directly onto a porous end surface of the elongate capillary body, and

wherein a resistance of the at least one heating element decreases towards a center of the porous end surface to vary the heating profile of the electric heater across the porous end surface.

2. The heater assembly according to claim 1 , wherein the electrically conductive material of the at least one heating element is at least partially diffused into the porous end surface of the elongate capillary body.

3. The heater assembly according to claim 1 , wherein the at least one heating element comprises a printable electrically conductive material printed on the porous end surface of the elongate capillary body.

4. The heater assembly according to claim 1 , wherein the electrically conductive material comprises one or more of a metal, an electrically conductive polymer, and an electrically conductive ceramic.

5. The heater assembly according to claim 1 , wherein a cross-sectional area of the at least one heating element increases towards a center of the porous end surface to vary the heating profile of the electric heater.

6. The heater assembly according to claim 1 ,

wherein spacing between adjacent parts of the at least one heating element defines a plurality of apertures in the electric heater, and

wherein a size of the apertures varies to vary the heating profile of the electric heater.

7. The heater assembly according to claim 1 , wherein the electric heater comprises at least one heating element formed from a first electrically conductive material and at least one heating element formed from a second electrically conductive material different than the first electrically conductive material, the first and the second electrically conductive materials being deposited directly onto the porous end surface of the elongate capillary body.

8. The heater assembly according to claim 1 , wherein the electric heater comprises first and second electrically conductive contact portions in electrical contact with the at least one heating element, the first and the second electrically conductive contact portions being formed from an electrically conductive material deposited directly onto the porous end surface of the elongate capillary body.

9. The heater assembly according to claim 1 ,

wherein the elongate capillary body includes a first capillary material and a second capillary material,

wherein the at least one heating element is formed from an electrically conductive material deposited directly onto a porous end surface of the first capillary material, and

wherein the second capillary material is in contact with the first capillary material and spaced apart from the heater assembly by the first capillary material, the first capillary material having a higher thermal decomposition temperature than that of the second capillary material.

10. A cartridge for an aerosol-generating system, the cartridge comprising:

a liquid storage portion configured to hold a liquid aerosol-forming substrate; and

a heater assembly, comprising:

an electric heater having at least one heating element configured to heat the liquid aerosol-forming substrate to form an aerosol; and

an elongate capillary body configured to convey the liquid aerosol-forming substrate from the liquid storage portion of the aerosol-generating system to the at least one heating element,

wherein the at least one heating element is formed from an electrically conductive material deposited directly onto a porous end surface of the elongate capillary body, and

wherein a resistance of the at least one heating element decreases towards a center of the porous end surface to vary the heating profile of the electric heater across the porous end surface.

11. The cartridge according to claim 10 ,

wherein the elongate capillary body comprises a first end extending into the liquid storage portion and being configured to contact liquid therein, and a porous second end opposite to the first end, and

wherein the at least one heating element is formed from an electrically conductive material deposited directly onto the second end of the elongate capillary body.

12. An aerosol-generating system, comprising:

an aerosol-generating device; and

a cartridge comprising:

a liquid storage portion configured to hold a liquid aerosol-forming substrate; and

a heater assembly, comprising:

an electric heater having at least one heating element configured to heat the liquid aerosol-forming substrate to form an aerosol; and

an elongate capillary body configured to convey the liquid aerosol-forming substrate from the liquid storage portion of the aerosol-generating system to the at least one heating element,

wherein the at least one heating element is formed from an electrically conductive material deposited directly onto a porous end surface of the elongate capillary body,

wherein a resistance of the at least one heating element decreases towards a center of the porous end surface to vary the heating profile of the electric heater across the porous end surface,

wherein the cartridge is removably coupled to the aerosol-generating device, and

wherein the aerosol-generating device includes a power supply for the heater assembly.

13. The aerosol-generating system according to claim 12 , wherein the aerosol-generating system is an electrically operated smoking system.

14. A method of manufacturing a cartridge for an aerosol-generating system, the method comprising:

providing a liquid storage portion for holding a liquid aerosol-forming substrate;

providing an elongate capillary body having a porous end surface;

forming an electric heating element by depositing an electrically conductive material directly onto the porous end surface of the elongate capillary body, wherein a resistance of the at least one heating element decreases towards a center of the porous end surface to vary the heating profile of the electric heater across the porous end surface;

filling the liquid storage portion with liquid aerosol-forming substrate; and

connecting the elongate capillary body to the liquid storage portion such that liquid aerosol-forming substrate contained in the liquid storage portion is conveyed from the liquid storage portion to the electric heating element by the elongate capillary body.

15. The method according to claim 14 , wherein the electrically conductive material is deposited by printing a printable electrically conductive material directly onto the porous end surface of the elongate capillary body.

16. The method according to claim 15 , wherein the printable electrically conductive material comprises one or more additives selected from a group consisting of: solvents, curing agents, adhesion promoters, surfactants, viscosity reduction agents, and aggregation inhibitors.