A heat pipe is provided having a vessel with a closed first end, a second end, and a wick on an inner surface that defines a passageway. A convex wall is positioned at the second end so as to block the passageway. The convex wall is deformable so as to move from a first position wherein a portion of the wall is convex to a second position wherein the portion of the wall is concave. The convex wall may include at least one stress concentrator so that upon an application of a force to the convex wall, the stress concentrator causes the convex wall to buckle. A method for forming the above-described heat pipe is also provided.