Aerosol Generating Article

Abstract

An aerosol generating article includes an airflow channel, a substrate for generating an aerosol, wherein the substrate is disposed inside the airflow channel and a valve disposed inside the airflow channel, the valve having an open state and a closed state, wherein the valve is configured to restrict air flow through the airflow channel when in the closed state relative to when in the open state. The valve includes a shape memory alloy arranged such that the valve changes from the closed state to the open state when heated to a transition temperature of the shape memory alloy.

1 . An aerosol generating article comprising:
 an airflow channel;   a substrate for generating an aerosol, wherein the substrate is disposed inside the airflow channel;   a valve disposed inside the airflow channel, the valve having an open state and a closed state, wherein the valve is configured to restrict air flow through the airflow channel when in the closed state relative to when in the open state, and wherein at least a portion of the valve comprises a shape memory alloy material arranged such that the valve changes from the closed state to the open state when heated to a transition temperature of the shape memory alloy material.   
     
     
         2 . The aerosol generating article of  claim 1 , wherein the shape memory alloy material is configured to be in a first form when the valve is in the closed state and to be in a second form when the valve is in the open state, and wherein the shape memory alloy material is arranged such that when heated to the transition temperature while in the first form, the shape memory alloy material transitions from the first form to the second form so as to change the valve from the closed state to the open state. 
     
     
         3 . The aerosol generating article of  claim 1 , wherein the valve comprises:
 a flap arranged to substantially close the airflow channel when the valve is in the closed state; and   an actuating portion that comprises the shape memory alloy material and is mechanically connected to the flap, wherein the actuating portion is arranged such that when the valve is heated to the transition temperature while the valve is in the closed state, the actuating portion moves the flap so as to open the airflow channel.   
     
     
         4 . The aerosol generating article of  claim 3 , wherein the actuating portion and the flap are integral with one another. 
     
     
         5 . The aerosol generating article of  claim 1 , wherein the shape memory alloy material is configured to be substantially planar when the valve is in the open state. 
     
     
         6 . The aerosol generating article of  claim 1 , wherein the shape memory alloy material has a Curie temperature of less than 200° C. 
     
     
         7 . The aerosol generating article of any  claim 1 , wherein the valve is inductively heatable. 
     
     
         8 . The aerosol generating article of  claim 1 , further comprising one or more inductively heatable susceptors for heating the substrate, the one or more inductively heatable susceptors being disposed inside the airflow channel. 
     
     
         9 . The aerosol generating article of  claim 1 , further comprising a filter for filtering the aerosol generated by substrate. 
     
     
         10 . An aerosol generating system comprising:
 the aerosol generating article of  claim 1 ; and   a heating device arranged to heat the substrate in use.   
     
     
         11 . The aerosol generating system of  claim 10 , wherein the aerosol generating article comprises one or more inductively heatable susceptors for heating the substrate, the one or more inductively heatable susceptors being disposed inside the airflow channel. 
     
     
         12 . The aerosol generating system of  claim 11 , wherein the heating device comprises an inductor that is configured to produce, in use, an oscillating magnetic field suitable for heating the one or more inductively heatable susceptors. 
     
     
         13 . The aerosol generating system of  claim 12 , wherein the inductor comprises an electrically-powered coil. 
     
     
         14 . The aerosol generating article of  claim 1 , wherein the shape memory alloy material has a Curie temperature of less than 100° C.