Tough supersoft sponge fibers with tunable stiffness from a DNA self-assembly technique

Tough and soft: Highly porous, spongelike materials self-assemble by calcium ion condensation of DNA-wrapped carbon nanotubes (SWNTs–DNA; see picture, IL=ionic liquid). The toughness, modulus, and swellability of the electrically conductive sponges can be tuned by controlling the density and strength of interfiber junctions. The sponges have compliances similar to the softest natural tissue, while robust interfiber junctions give high toughness.