Metamaterials are artificial substances endowed with properties which are absent in nature. Jong Bum Lee, Cornell University, New York, USA, and colleagues created a novel organic-based metamaterial possessing unique mechanical features.
The researchers designed a two-step DNA polymerization reaction to generate long single- and double-strand DNA molecules and intertwine them noncovalently into a hydrogel. This enzymatic reaction produced a metagel with an unconventional internal structure that conferred the material unique features. Thanks to its hierarchical and porous nanostructure, the hydrogel could change its state from solid to liquid depending on the presence or absence of water, respectively. When liquid, moreover, the hydrogel adopted many different shapes and returned to the original one upon addition of water.
The scientists demonstrated that this hydrogel can be used in electronics, to create electrical circuits employing water as a current switch, or in medicine as a controlled drug release system.
- A mechanical metamaterial made from a DNA hydrogel,
J. B. Lee, S. Peng, D. Yang, Y. H. Roh, H. Funabashi, N. Park, E. J. Rice, L. Chen, R. Long, M. Wu, D. Luo,
Nature Nanotech. 2012, 7(12), 816–820.