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“These wires are the building blocks for future nanoelectronics.”
Silicon nanowires are attracting significant attention from the electronics industry due to the drive for ever-smaller electronic devices, from cell phones to computers. The operation of these future devices, and a wide array of additional applications, will depend on the mechanical properties of these nanowires.
New NC State research shows that silicon nanowires are far more resilient than their larger “bulk” counterparts, a finding that could pave the way for smaller, sturdier nanoelectronics, nanosensors, light-emitting diodes and other applications.
“The mainstream semiconductor industry is built on silicon,” says Dr. Yong Zhu, assistant professor of mechanical engineering and lead researcher on this project. “These wires are the building blocks for future nanoelectronics.”
The researchers set out to determine how much abuse these silicon nanowires can take. How do they deform — meaning how much can you stretch or warp the material before it breaks? And how much force can they withstand before they fracture or crack?
As it turns out, silicon nanowires deform in a very different way from bulk silicon, which is brittle and can’t be stretched or warped very much without breaking.
“The silicon nanowires are more resilient and can sustain much larger deformation,” said Feng Xu, a Ph.D. student in mechanical engineering. “Other properties of silicon nanowires include increasing fracture strength and decreasing elastic modulus as the nanowire gets smaller and smaller.”
The fact that silicon nanowires have more deformability and strength is a big deal, said the researchers, who also include Ph.D. student Qingquan Qin and researchers at the University of Michigan.
“The insights gained from this study not only advance fundamental understanding
about size effects on mechanical properties of nanostructures,” Zhu said, “but
also give designers more options in designing nanodevices ranging from nanosensors
to nanoelectronics to nanostructured solar cells.”
