A micro-vaporizer comprising: a main body having a main body interior; a vaporization chamber disposed within the main body interior; a vaporizable liquid reservoir disposed within the main body configured for selectively retaining a vaporizable liquid; a heating element disposed within the vaporization chamber and configured to selectively heat and vaporize vaporizable liquid drawn from the liquid reservoir; one or more air inlet openings in the main body collectively defining an air intake portal; an air flow passage from the air intake portal to the vaporization chamber, the air flow passage providing a first fluid communication path between the vaporization chamber and an ambient environment external to the main body; a vaporization products flow passage from the vaporization chamber to an exit port, the vaporization products flow passage providing a second fluid communication path between the vaporization chamber and the ambient environment external to the main body; a first air-permeable liquid barrier comprising a first porous medium having a plurality of flow passages formed therethrough and disposed within the air flow passage, the first air-permeable liquid barrier being configured to inhibit passage of the vaporizable liquid through the air flow passage; and characterized by: a second air-permeable liquid barrier comprising a second porous medium having different flow properties from the first porous medium disposed within the vaporization products flow passage, the second air-permeable liquid barrier being configured to inhibit passage of the vaporizable liquid through the vaporization products flow passage. a main body having a main body interior; a vaporization chamber disposed within the main body interior; a vaporizable liquid reservoir disposed within the main body configured for selectively retaining a vaporizable liquid; a heating element disposed within the vaporization chamber and configured to selectively heat and vaporize vaporizable liquid drawn from the liquid reservoir; one or more air inlet openings in the main body collectively defining an air intake portal; an air flow passage from the air intake portal to the vaporization chamber, the air flow passage providing a first fluid communication path between the vaporization chamber and an ambient environment external to the main body; a vaporization products flow passage from the vaporization chamber to an exit port, the vaporization products flow passage providing a second fluid communication path between the vaporization chamber and the ambient environment external to the main body; a first air-permeable liquid barrier comprising a first porous medium having a plurality of flow passages formed therethrough and disposed within the air flow passage, the first air-permeable liquid barrier being configured to inhibit passage of the vaporizable liquid through the air flow passage; and characterized by: a second air-permeable liquid barrier comprising a second porous medium having different flow properties from the first porous medium disposed within the vaporization products flow passage, the second air-permeable liquid barrier being configured to inhibit passage of the vaporizable liquid through the vaporization products flow passage.