title: A mechanical metamaterial made from a DNA hydrogel.
abstract: Metamaterials are artificial substances that are structurally engineered to have properties not typically found in nature. To date, almost all metamaterials have been made from inorganic materials such as silicon and copper, which have unusual electromagnetic or acoustic properties that allow them to be used, for example, as invisible cloaks, superlenses or super absorbers for sound. Here, we show that metamaterials with unusual mechanical properties can be prepared using DNA as a building block. We used a polymerase enzyme to elongate DNA chains and weave them non-covalently into a hydrogel. The resulting material, which we term a meta-hydrogel, has liquid-like properties when taken out of water and solid-like properties when in water. Moreover, upon the addition of water, and after complete deformation, the hydrogel can be made to return to its original shape. The meta-hydrogel has a hierarchical internal structure and, as an example of its potential applications, we use it to create an electric circuit that uses water as a switch.
authors.affiliation: Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Jong Bum
authors.initials: JB
authors.lastname: Lee
authors.forename: Songming
authors.initials: S
authors.lastname: Peng
authors.forename: Dayong
authors.initials: D
authors.lastname: Yang
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Roh
authors.forename: Hisakage
authors.initials: H
authors.lastname: Funabashi
authors.forename: Nokyoung
authors.initials: N
authors.lastname: Park
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Rice
authors.forename: Liwei
authors.initials: L
authors.lastname: Chen
authors.forename: Rong
authors.initials: R
authors.lastname: Long
authors.forename: Mingming
authors.initials: M
authors.lastname: Wu
authors.forename: Dan
authors.initials: D
authors.lastname: Luo
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D001709:Biotechnology / Q000379:methods; D004247:DNA / Q000138:chemical synthesis*; D017931:DNA Primers / Q000378:metabolism; D020100:Hydrogels / Q000138:chemical synthesis*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D011108:Polymers / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D017931:DNA Primers; D020100:Hydrogels; D011108:Polymers; D004247:DNA