Pressure sensitive device for flow detection

An electronic inhalation device, comprising:

• a chamber having a material to be dispersed;
• a pressure sensitive device mounted within a hollow tube having a longitudinal axis and configured to permit air suction through one end portion of the tube, the pressure sensitive device including:
• a ring fixedly mounted in the tube and having a central axis, a first side and a second side, the ring including a dielectric portion parallel to the central axis and between the first side and the second side;
• a flexible membrane disposed in the tube and mounted directly on a periphery of the ring on the first side, the flexible membrane including a conductive portion;
• and
• a perforated membrane disposed in the tube and connected to a periphery of the ring on the second side, the second side being closer to the one end portion that permits air suction therethrough relative to the first side, the perforated membrane being spaced apart and electrically isolated from the flexible membrane by the ring below a threshold pressure differential across the pressure sensitive device within the tube, the perforated membrane including an opening therethrough and a conductive portion facing and corresponding to the conductive portion of the flexible membrane;
• and
• a circuit having an element coupled to a battery such that a threshold pressure differential along the longitudinal direction of the tube across the pressure sensitive device causes the flexible membrane to be drawn into the perforated membrane by the suction such that deflection between the conductive portions of the flexible membrane and the perforated membrane enables the element to dispense the material in the chamber and draw out the material from the chamber by the pressure differential.