Fracture Analysis of Silicon Nanowire for NEMS - In-Situ Nanomanipulation with SEM

By AZoM.com Staff Writers

Table of Content

Introduction
Challenge in Fracture Analysis of Nanowires
Fracture Analysis of Nanowires Using miBot Nanomanipulator
Conclusion
About Imina Technologies

Introduction

Nanowire resonators exhibit high resonant frequencies and quality factors, which enable these nano-electromechanical systems (NEMS) of high interest to be served as resonators and switches in a myriad of applications.

The pull-in and resonator properties of nanowire resonators are critical for these applications. Hence, the strength of clamping must be evaluated during the application of a bending force.

Challenge in Fracture Analysis of Nanowires

Since the nanowire under test is only a few micrometers in length and a hundred nanometers wide, displacing it with the necessary motion and positioning resolutions is a challenging task. This can be addressed with the use of the miBot nanomanipulator from Imina Technologies.

Fracture Analysis of Nanowires Using miBot Nanomanipulator

Figure 1. Single-crystal silicon nanowire fabricated from etching a silicon on insulator (SOI) wafer

In this experiment, single-crystal silicon nanowires (SiNWs) of 50 µm length and 194nm diameter with clamped ends are displaced at their middle by a combination of a miBot nanomanipulator and a 500nm tungsten probe under SEM, as shown in Figure 1.

As depicted in Figure 2, the SiNWs are gradually displaced until fracture takes place either at the clamping points or at some other points in the wires to measure the clamping or fracture strengths, respectively.

Figure 2. Loading of the silicon nanowire with the miBot nanomanipulator probe (left); displacement just before fracture (middle); and COMSOL model showing calculated stresses at the loading point

This data is obtained by observing the displacements until the onset of failure under SEM. The resulting data is then applied in a large-scale displacement model in COMSOL to measure the fracture strengths.

Conclusion

The nanometer positioning resolution and high mechanical stability of the miBot nanomanipulator made this experiment possible by enabling the displacement of the SiNW until fracture with vibration-free motion. In addition, the miBot was able to quickly move into the correct position to apply the force normal to the nanowire under the SEM, thanks to its mobility of four degrees of freedom.

About Imina Technologies

Imina Technologies is a privately held company founded in 2009 to exploit more than ten years of research in high precision robotics at the Swiss Federal Institute of Technology in Lausanne, Switzerland (EPFL). With many years of experience in precision engineering, micro-robotics and nanomanipulation, Imina's interdisciplinary team is geared up for the needs of the most demanding users. Their unique combination of know-how enables them to propose complete solutions for even the most specific applications.

Imina Technologies introduces a new type of micro- and nanomanipulators. Based on a novel motion technology, the miBot is the world's smallest manipulator. It combines nanometer resolution of positioning, unprecedented ease-of-use and flexibility in an ultra compact design. Complete solutions of nanomanipulation are provided to quickly integrate the systems in electron microscopes (SEM/FIB) and light microscopes. The handling of samples like nanowires, MEMS or cells is effortless, speeding-up the production of experimental results.

This information has been sourced, reviewed and adapted from materials provided by Imina Technologies.

For more information on this source, please visit Imina Technologies.

 

Date Added: Aug 28, 2013 | Updated: Aug 28, 2013
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