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 research from North Carolina State University shows that silicon nanowires are far more resilient than their larger counterparts, a finding that could pave the way for smaller, sturdier nanoelectronics, nanosensors, light-emitting diodes and other applications.
It is no surprise that the mechanical properties of silicon nanowires are different from "bulk" or regular size silicon materials, because as the diameter of the wires decrease, there is an increasing surface-to-volume ratio. Unfortunately, experimental results reported in the literature on the properties of silicon nanowires have reported conflicting results. So the NC State researchers set out to quantify the elastic and fracture properties of the material.
"The mainstream semiconductor industry is built on silicon," says Dr. Yong Zhu, assistant professor of mechanical engineering at NC State and lead researcher on this project. "These wires are the building blocks for future nanoelectronics." For this study, 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? The researchers focused on nanowires made using the vapor-liquid-solid synthesis process, which is a common way of producing silicon nanowires.
Zhu and his team measured the nanowire properties using in-situ tensile testing inside scanning electron microscopy. A nanomanipulator was used as the actuator and a micro cantilever used as the load sensor. "Our experimental method is direct but simple," says Qingquan Qin
|Contact: Matt Shipman|
North Carolina State University