Nanohelix fashions nanometre-scale sensors

A previously unknown zinc oxide nanostructure that resembles the helical configuration of DNA could provide engineers with a new building block for creating nanometre -scale sensors, transducers, resonators and other devices that rely on electromechanical coupling.

Based on a superlattice composed of alternating single-crystal “stripes” just a few nanometres wide, the “nanohelix” structure is part of a family of nanobelts – tiny ribbon-like structures with semiconducting and piezoelectric properties – that were first reported in 2001.

The nanohelices, which get their shape from twisting forces created by a small mismatch between the stripes, are produced using a vapour-solid growth process at high temperature. Information about the growth and analysis of the new structures will be reported in the September 9 issue of the journal Science.

“This structure provides a new building block for nanodevices,” said Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. “From them we can make resonators, place molecules on their surfaces to create frequency shifts, and because they are piezoelectric, make electromechanical couplings. This adds a new structure to the toolbox of nanomaterials.”