The present invention relates to an
aerosol-generating
system comprising a
liquid storage portion for storing liquid
aerosol-forming substrate, wherein the
liquid storage portion comprises a movable wall and an outlet, a vaporiser comprising a
heating element having a structure defining an open-ended internal passage for heating deposited liquid
aerosol-forming substrate, a pump configured for delivering liquid aerosol-forming substrate from the outlet of the
liquid storage portion to the internal passage of the
heating element, the pump comprising a micro
stepper motor with a
drive shaft thatis configured to rotate for a predetermined amount upon performing one step of the micro
stepper motor, a
piston connected to the movable wall, and a lead screw connecting the
drive shaft to the
piston and configured to translate a rotation of the
drive shaft into an axial movement of the
piston and a corresponding axial movement of the movable wall, wherein the vaporiser is configured for heating the delivered liquid aerosol-forming substrate in the internal passage to a temperature sufficient to volatilize at least a part of the delivered liquid aerosol-forming substrate. The present invention further relates to a
cartridge for an aerosol-generating
system, wherein the
cartridge comprises the liquid storage portion, the piston, and the lead screw. The present invention further relates to a method for generating aerosol.