In various embodiments, a memory device includes at least one memory cell and at least one virtual supply line coupled to the at least one memory cell. The delivering module includes a paper tray for supporting at least one paper, at least one roller attached on the paper tray for delivering the at least one paper, and a blocking member pivotably attached to the paper tray. The coating is grafted onto a low density foam substrate to provide the low density foam substrate protection from abrasions, tears, scratches, ozone and UV light, while maintaining the flexibility of the foam substrate.