Centimeter-Long Single-Crystalline Si Nanowires

The
elongation of free-standing one-dimensional (1D) functional
nanostructures into lengths above the millimeter range has brought
new practical applications as they combine the remarkable properties
of nanostructured materials with macroscopic lengths. However, it
remains a big challenge to prepare 1D silicon nanostructures, one
of the most important 1D nanostructures, with lengths above the millimeter
range. Here we report the unprecedented preparation of ultralong single-crystalline
Si nanowires with length up to 2 cm, which can function as the smallest
active material to facilitate the miniaturization of macroscopic devices.
These ultralong Si nanowires with augmented flexibility are of emerging
interest for flexible electronics. We also demonstrate the first single-nanowire-based
wearable joint motion sensor with superior performance to reported
systems, which just represents one example of novel devices that can
be built from these nanowires. The preparation of ultralong Si nanowires
will stimulate the fabrication and miniaturization of electric, optical,
medical, and mechanical devices to impact the semiconductor industry
and our daily life in the near future.