Nano-scale deformation measurement solutions
Nano Solutions Technology, Inc. has exclusively licensed Nano-Vic from Correlated Solutions, Inc. Nano-Vic is a software package that offers a nanoscale mechanical deformation measurement solutions for materials characterization and testing.
Nano-Vic is based on the professional standard in two-dimensional digital image correlation, providing full-field, in-plane deformation analysis of images from AFM, SEM and other high resolution microscopes. The new software analyzes series of images from samples that have undergone some form of micro or nano mechanical testing and applies a patented video image correlation technique to produce deformation data.
The software is sensitive to minute changes occuring at extremely low loads (in the nano-newton to pico-newton range). This is of great importance to the development and reliability of nano materials, structures, coatings and devices.
Nano-Vic provides detailed analysis of nanomechanical deformation such as wear, strain and compression. This type of data is not readily available with standard topography imaging from instruments such as AFM and SEM.
Do you have a micro or nano mechanical application? Contact Nanounity to discuss your application or run a data set to see what Nano-Vic can do for you.
Applications
The Nano-Vic system is used where strain distributions need to be measured on two dimensional digital images of specimens. Applications include fracture mechanics (COD measurement), bi-axial tension tests of films, determination of strain localization around cracks, notches and non-homogeneous material interfaces. At the nanoscale, Nano-Vic is ideal for determining the localized effects of subcomponent interaction such as the introduction of carbon nanotubes to a polymer blend.
Nano-Vic can be used to determine the full-field correlation coefficient (used as a confidence factor to determine the suitability of scans used for analysis), and then to extract localized strain data. The correlation coefficient, Exx, Eyy and Exy are mapped over the entire data field with accuracy down to the sub-pixel.
Nano-Vic can measure in-plane displacements and strain from 500 micro strain to 500% strain and above, for specimen sizes ranging from <1mm to >10m. Setup is simple and requires only an applied random speckle pattern on the specimen. No special illumination or lasers are required.
The set of images to the right demonstrate a standard application of the Nano-Vic package. All of the images shown were acquired from the same sample while incremental strain was applied. The top two images show a speckle pattern on an aluminum sample with two offset semi-circular cut-outs. A digital camera monitored the sample as incremental strain was applied. The two images were selected from the beginning and very end of the test to show the sensitivity across the range of strain applied during the test. Since the deformation is predominantly in-plane, a single camera was used to measure the deformation.
The bottom two images show the horizontal strain measured by two-dimensional image correlation for the top two images.
Nano-Vic applications in nanotribology
Nanotribology has been enabled by the commercialization of the Atomic Force Microscope (AFM) and techniques developed for testing surface interfacial phenomenon at a micro and nano scale. With these tools, scientist and engineers have new methods for characterizing micro and nano scale friction, lubrication and wear. In addition to AFM, an entire field of niche tools has been developed to test and characterize nanomechanical interactions by means of nanoindentation, nanoscratch and nanotensile testing.
The ability to characterize coating and surface wear at extremely low loads (in the range of nano/piconewtons) are of great importance to the development and reliability of structures and devices such as MEMS, NEMS and magnetic storage.
In the following examples, six different AFM scans were collected of a Au coated surface. Wear testing with an AFM probe was performed during each scan. The force used was incrementally increased from one image to the next throughout the test.
After the scanning was complete the data was processed by the Nano-Vic image correlation software. The analysis shows the areas of each scan that underwent plastic deformation. The following deformation maps were overlaid on top of each AFM scan and shows the amount of force applied during each scan.