Abstract: A cartridge for an aerosol-generating system includes a liquid storage portion configured to store a liquid aerosol-forming substrate. The liquid storage portion includes one or more flexible walls and is configured to change at least one of the shape and the size of the liquid storage portion upon a change of the volume of the liquid aerosol-forming substrate held in the liquid storage portion. The cartridge includes a sensor configured to detect data of a physical property. The data relates to at least one of a corresponding shape and a corresponding size of the liquid storage portion so that the volume of the liquid aerosol-forming substrate held in the liquid storage portion is determinable from the measured data.

Abstract: A liquid storage portion for an aerosol-generating system includes a container configured to hold a liquid aerosol-forming substrate. The container has an opening for dispensing the liquid aerosol-forming substrate, and includes at least one transparent wall portion, such that the liquid level in the container can be visually monitored by the vaper. The container is further configured such that the liquid aerosol-forming substrate is held in a contiguous volume area of the container. The aerosol-forming substrate in the contiguous volume is confined near the dispensing opening of the container without regard to the orientation of the liquid storage portion.

Abstract: A cartridge for an aerosol-generating system includes a sensor including a capacitor with a first capacitor plate and a second capacitor plate, a storage portion for storing an aerosol-forming substrate, and a vaporizer. The storage portion is between the first capacitor plate and the second capacitor plate. The permittivity of the liquid storage portion changes upon a change of the volume f the liquid aerosol-forming substrate held in the liquid storage portion. The sensor is configured to measure the capacitance of the capacitor. The measured capacitance relates to a corresponding permittivity of the aerosol-forming substrate held in the storage portion so that the amount of the volume of the aerosol-forming substrate held in the storage portion is determinable from the measured capacitance.