Cartridge with a capacity sensor

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 of 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.

We claim: 
     
         1 . A cartridge for an aerosol-generating system, the cartridge comprising:
 a capacitor including,
 a first capacitor plate defining a central air passage, and 
 a second capacitor plate; 
   a storage portion configured to store an aerosol-forming substrate, the storage portion between the first capacitor plate and the second capacitor plate;   a wick in communication with the storage portion, at least a portion of the wick extending perpendicular to the central air passage;   a vaporizer in the central air passage, the vaporizer surrounding at least a portion of the wick; and   a controller configured to, based on a measured capacitance of the capacitor, calculate a remaining amount of the aerosol-forming substrate.   
     
     
         2 . The cartridge according to  claim 1 , wherein the storage portion comprises:
 a capillary medium configured to store the aerosol-forming substrate.   
     
     
         3 . The cartridge according to  claim 1 , wherein the first capacitor plate and the second capacitor plate each have a generally cylindrical shape. 
     
     
         4 . The cartridge according to  claim 3 , wherein the first capacitor plate is located within a volume defined by the second capacitor plate. 
     
     
         5 . The cartridge according to  claim 1 , wherein the first capacitor plate and the second capacitor plate are concentric. 
     
     
         6 . The cartridge according to  claim 1 , further comprising:
 a sensor configured to measure a capacitance of the capacitor; and   wherein the controller is configured to determine a volume of the storage portion dependent on an output of the sensor.   
     
     
         7 . The cartridge according to  claim 1 , wherein a permittivity of the storage portion is configured to change upon a change of a volume of the aerosol-forming substrate held in the storage portion. 
     
     
         8 . The cartridge according to  claim 1 , wherein the aerosol-forming substrate within the storage portion is free flowing. 
     
     
         9 . The cartridge according to  claim 8 , further comprising:
 a tilt sensor configured to sense whether the aerosol-forming substrate held in the storage portion has a level that is perpendicular to the first capacitor plate and the second capacitor plate.   
     
     
         10 . The cartridge according to  claim 1 , wherein ends of the wick are between the first capacitor plate and the second capacitor plate. 
     
     
         11 . An aerosol-generating system comprising:
 a main unit including,
 a power supply; and 
 a cartridge removably coupled to the main unit, the cartridge including,
 a capacitor including, 
 a first capacitor plate defining a central air passage, and 
 a second capacitor plate, 
 
 a storage portion configured to store an aerosol-forming substrate, the storage portion between the first capacitor plate and the second capacitor plate, 
 a wick in communication with the storage portion, at least a portion of the wick extending perpendicular to the central air passage and at least a portion of the wick between the first capacitor plate and the second capacitor plate, 
 a vaporizer in the central air passage and surrounding at least a portion of the wick, 
 a controller configured to, based on a measured capacitance of the capacitor, calculate a remaining amount of the aerosol-forming substrate, and 
 a memory, the capacitor, and the controller each included in one of the main unit and the cartridge. 
   
     
     
         12 . The aerosol-generating system according to  claim 11 , wherein the storage portion comprises:
 a capillary medium configured to store the aerosol-forming substrate.   
     
     
         13 . The aerosol-generating system according to  claim 11 , wherein the first capacitor plate and the second capacitor plate each have a generally cylindrical shape. 
     
     
         14 . The aerosol-generating system according to  claim 13 , wherein the first capacitor plate is located within a volume defined by the second capacitor plate. 
     
     
         15 . The aerosol-generating system according to  claim 11 , wherein the first capacitor plate and the second capacitor plate are concentric. 
     
     
         16 . The aerosol-generating system according to  claim 11 , further comprising:
 a sensor configured to measure a capacitance of the capacitor; and   wherein the controller is configured to determine a volume of the storage portion dependent on an output of the sensor.   
     
     
         17 . The aerosol-generating system according to  claim 11 , wherein a permittivity of the storage portion is configured to change upon a change of a volume of the aerosol-forming substrate held in the storage portion. 
     
     
         18 . The aerosol-generating system according to  claim 11 , wherein the aerosol-forming substrate within the storage portion is free flowing. 
     
     
         19 . The aerosol-generating system according to  claim 18 , further comprising:
 a tilt sensor configured to sense whether the aerosol-forming substrate held in the storage portion has a level that is perpendicular to the first capacitor plate and the second capacitor plate.   
     
     
         20 . The aerosol-generating system according to  claim 11 , wherein ends of the wick are between the first capacitor plate and the second capacitor plate.