An interposer device comprising a first conductor pattern on a first side defining a portion of the interposer device to be covered by a first electrical circuit element; and a second conductor pattern on a second side to be connected to a second electrical circuit element. The second conductor pattern is electrically coupled to the first conductor pattern. The interposer device further comprises a plurality of nanostructure energy storage devices arranged within the portion of the interposer device to be covered by the first electrical circuit element. Each of the nanostructure energy storage devices comprises at least a first plurality of conductive nanostructures; a conduction controlling material embedding the nanostructures; a first electrode connected to each nanostructure in the first plurality of nanostructures; and a second electrode separated from each nanostructure in the first plurality of nanostructures by the conduction controlling material.