NOVELTY - Hydrogen storage apparatus comprises a foldable polymer backbone comprising physico-chemically-linked hydrogen-affine host complexes; mechanism for stimulating the polymer backbone to controllably fold and unfold the backbone to cause hydrogen inclusion and release by the hydrogen-affine host complexes; and mechanism for controllably activating the hydrogen-affine host complexes to uptake or release the hydrogen.    USE - Apparatus for storing hydrogen useful for portable and distributed power generation, including transportation fuel cells applications.    ADVANTAGE - The apparatus provides hydrogen storage that achieves ultra-high storage density due to large internal surface area available for hydrogen inclusion; ease and fastness of hydrogen release upon thermal, chemical, mechanical, magnetic, electrical or light actuation; use of synthesis or naturally occurring backbone materials; reversible hydrogen uptake/release; and convenient recycling. The hydrogen storage media provides high energy capacity, high power density hydrogen storage based on folding and unfolding of a polymer backbone comprising a hydrogen host complex, with on-demand chemical, thermal, mechanical, magnetic, electrical or photo (light) actuation of hydrogen uptake and release.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for hydrogen storage comprising:    (1) forming a polymer backbone;    (2) physico-chemically-linking hydrogen-affine host complexes to the polymer backbone, to form a folded polymer backbone having physico-chemically-linked hydrogen-affine host complexes;    (3) stimulating the polymer backbone to unfold the backbone and prepare for receiving hydrogen;    (4) incorporating hydrogen in hydrogen-affine host complexes of the unfolded polymer backbone;    (5) folding the polymer backbone with incorporated hydrogen;    (6) unfolding folded polymer backbone having incorporated hydrogen; and    (7) activating the hydrogen-affine host complexes to release the hydrogen.    The mechanism for stimulating folding and unfolding of the polymer backbone and the mechanism for activating the hydrogen-affine host complexes comprise thermal stimulation, chemical stimulation, mechanical stimulation, magnetic stimulation, electrical stimulation, or optical stimulation mechanism. The mechanical stimulation mechanism comprises pressure, shear stress, vibration or sonication.