There is provided a heater assembly for an aerosol-generating system including a liquid storage portion configured to hold a liquid aerosol-forming substrate, the heater assembly including an electric heater having at least one heating element configured to heat the liquid aerosol-forming substrate to form an aerosol, and a 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, the at least one heating element being formed from an electrically conductive material deposited directly onto a porous outer surface of the capillary body. A cartridge for an aerosol-generating system and a method for manufacturing such a cartridge are also provided.