Nanowires have the potential to aid in the next generation of electronic devices and computer components. Current research suggests that nanowires may soon be used to greatly enhance the capabilities of transistors, memory devices, and sensors.
Nanowire properties are greatly affected by the shape and structure of the wire if it is mechanically deformed. This is where Zimmerman’s research comes in. He performs simulations to predict how nanowires deform, when they fail and through which physical mechanisms, and how nanowire geometry influences this failure process. Zimmerman’s research provides the information necessary to efficiently implement nanowires in sensors and other microelectronic devices that are needed within Sandia’s systems.
With national security riding on his results, Zimmerman must use efficient methods to not only perform simulations, but to also display their results in the most useful manner. He has to make absolutely sure he is using the right tools for the job.
Using the Right Tools
Zimmerman’s various research projects have been aided by EnSight for over 7 years. Most recently, EnSight has helped him to provide the results of his nanowire simulations. Zimmerman uses specialized code, including ParaDyn and LAMMPS, to perform the nanowire simulations. He then uses EnSight to visualize and analyze his simulation results.
Using EnSight, he is able to demonstrate the properties of nanowires, as well as provide 3D renderings of the results. With EnSight, he can illustrate if or how a nanowire deforms under certain conditions.
Zimmerman said, “Our goal is to demonstrate the mechanics of nanowires under various conditions in order to develop a predictive understanding of nanowire behavior.”
“By being able to demonstrate the failure processes of the deformation of nanowires, we can better understand how and when to properly manipulate them for more efficient usage in a variety of technologies.”
An Atomistic Approach
Since many aspects of nanowires are not yet well understood, cutting edge techniques are being developed to study their behavior.
Zimmerman performs atomistic simulations and uses EnSight to provide a glimpse into the mechanical behavior and deformation mechanisms of nanowires.
Atomistic simulation, the computer modeling of defects in materials at the microscopic level, allows Zimmerman to verify fundamental characteristics of nanowires and how they are influenced by certain conditions.
With EnSight, Zimmerman is able to show how factors such as different tension and compression levels affect nanowires at the molecular level.
“Atomistic simulations enable us to quantify the strengths of these wires during tensile failure, discover the mechanisms responsible for mechanical failure, and determine how wire dimensions, loading rates, crystal orientation and material models impact these characteristics. EnSight helps us to easily visualize our results.”
Presenting the Results
The ability to fine-tune the results makes EnSight a great match for Zimmerman’s research. To be able to customize the look and feel of his results depending on the presentation method and audience makes the results that much more valuable.
“Sometimes, I need to isolate and show just certain aspects of the failure process. For example, I often need to display only items according to their value of strain (or stress).”
EnSight also allows Zimmerman to color his results based on specified parameters. Color coding makes it easy to quickly pinpoint and reference specific areas when presenting the results.
“I also like the fact that I can rotate the generated results and that I can make movies that show the nanowire structure from various perspectives. This way, the viewer can really understand what physical processes are occurring during the nanowire deformation.”
Zimmerman uses his EnSight-produced graphics in scientific papers, on web sites, and for presentations.
“EnSight adds a level of quality and understanding to my research, thereby allowing the results to be accessible by a wider audience.”
Nanobridge formation in Gold nanowires - stretching of nanowires to specific strains results in tailored multishell structures that are ideally suited for manipulation of biological molecules, high electrical conduction, and high strength nanocomposites.
Shape Memory Effect in Copper nanowires – stress-induced reorientation at low temperature (10K); load removal at low temperature; deformation undone at high temperature (>425K).