NOVELTY - First and second actuators are connected in opposition with an inner sleeve (16) to alternately move the inner sleeve in first and second positions. A control mechanism disables the actuation of the first or second actuator while enabling the actuation of the second or first actuator. The inner sleeve has a cylindrical outer surface and a cylindrical inside surface that encloses a chamber.    USE - For controlling air flow in zinc-air battery used to power portable and mobile device.    ADVANTAGE - Enables electrochemical cell to have longer shelf life. Enables electrochemical cell to be manufactured in a size sufficiently small for use in powering portable and mobile devices. Prevents oxidizer from reacting with an electrode except when an electrical load is attached and useful electrical current is being drawn from the cell.    DETAILED DESCRIPTION - The inner sleeve is formed with first openings (20) and an outer sleeve (14) is formed with second openings (18) which register with the first openings to open flow of air when the inner sleeve is in first position. The second openings are out of register with the first opening to close the flow of air when the inner sleeve is in second position. The zinc-air battery provided within the chamber comprises zinc which produces electrical current responsive to ingress of air to the battery. The outer sleeve has a cylindrical inside surface mounted in sliding contact on outer surface of the inner sleeve which is mounted for reciprocating movement along a longitudinal axis between first and second axially spaced positions relative to the outer sleeve. Each actuator is formed of a shape memory alloy material having a crystalline phase change transition temperature. The actuators change shape by contraction responsive to being heated through their respective transition temperatures by a control circuit.    DESCRIPTION OF DRAWING(S) - The figure is the isometric view of concentric pair of valve sleeves.    Outer sleeve (14)    Inner sleeve (16)    Openings (18)    Transverse segment (90)