Application Note | Surface Segmentation
Surface Boundary Measurement of Styrofoam Using 3D Profilometry
Segmenting a Surface into Grains with Simultaneous Topography and Reflected Intensity
Research & Experimental Testing
Craig Leising
Visual Design & Editorial
Andrew Shore
Introduction
In studies where the interface of surface features, patterns, shapes etc., are being evaluated for orientation, it will be useful to quickly identify areas of interest over the entire profile of measurement. By segmenting a surface into significant areas the user can quickly evaluate boundaries, peaks, pits, areas, volumes and many others to understand their functional role in the entire surface profile under study. For example, like that of a grain boundary imaging of metals, the importance of analysis is the interface of many structures and their overall orientation. By understanding each area of interest defects and or abnormalities within the overall area can be identified. Although grain boundary imaging is typically studied at a range surpassing Profilometer capability, and is only 2D image analysis, it is a helpful reference to illustrate the concept of what will be shown here on a larger scale along with 3D surface measurement advantages.
Why a 3D Non-Contact Profilometer Matters for Surface Separation Studies
Unlike other techniques such as touch probes or interferometry, the 3D Non Contact Profilometer, using axial chromatism, can measure nearly any surface, sample sizes can vary widely due to open staging and there is no sample preparation needed. Nano through macro range is obtained during surface profile measurement with zero influence from sample reflectivity or absorption, has advanced ability to measure high surface angles and there is no software manipulation of results. Easily measure any material: transparent, opaque, specular, diffusive, polished, rough etc. The technique of the Non Contact Profilometer provides an ideal, broad and user friendly capability to maximize surface studies when surface boundary analysis will be needed; along with the benefits of combined 2D & 3D capability.
ℹ️ Learn more about non-contact profilometry lab services for surface segmentation.
Measurement Objective
In this application the NANOVEA ST400 Profilometer is used to measure the surface area of Styrofoam. Boundaries were established by combining a reflected intensity file along with the topography, which are simultaneously acquired using the NANOVEA ST400. This data was then used to calculate different shape and size information of each Styrofoam “grain”.
NANOVEA ST400 Standard
Optical 3D Profilometer
Sample
Results: 2D Surface Boundary Measurement
Topography image (below left) masked by reflected intensity image (below right) to clearly define grain boundaries. All grains below 565 µm diameter have been ignored by applying filter.
Fig. 1: Topography (left) and reflected intensity (right) of the Styrofoam surface.
| Grain statistic | Value |
|---|---|
| Total number of grains | 167 |
| Total projected area occupied by the grains | 166.917 mm² (64.5962%) |
| Total projected area occupied by boundaries | 35.4038% |
| Density of grains | 0.646285 grains/mm² |
| Area | 0.999500 ± 0.491846 mm² |
| Perimeter | 9114.15 ± 4570.38 µm |
| Equivalent diameter | 1098.61 ± 256.235 µm |
| Mean diameter | 945.373 ± 248.344 µm |
| Min diameter | 675.898 ± 246.850 µm |
| Max diameter | 1312.43 ± 295.258 µm |
Table 1: Grain statistics from the 2D boundary measurement (mean ± standard deviation).
Results: 3D Surface Boundary Measurement
By using the 3D topography data obtained, the volume, height, peak, aspect ratio and general shape information can be analyzed on each grain. Total 3D area occupied: 2.525 mm³.
Fig. 3: Individual grain selected for 3D analysis (left) and 3D view of the Styrofoam surface (right).
Conclusion
In this application, we have shown how the NANOVEA 3D Non Contact Profilometer can precisely characterize the surface of Styrofoam. Statistical information can be gained over the entire surface of interest or on individual grains, whether they are peaks or pits. In this example all grains larger than a user defined size were used to show the area, perimeter, diameter and height. The features shown here can be critical to research and quality control of natural and pre fabricated surfaces ranging from bio medical to micromachining applications along with many others.
Frequently Asked Questions About Surface Boundary Measurement
What is surface boundary measurement?
Segmenting a surface into significant areas so that boundaries, peaks, pits, areas and volumes can be evaluated quickly for their functional role in the whole surface. Like grain boundary imaging of metals, it focuses on the interfaces between structures and their overall orientation, and helps identify defects or abnormalities.
How are grain boundaries found with a profilometer?
The NANOVEA ST400 acquires topography and reflected intensity simultaneously. Masking the topography image with the reflected intensity image clearly defines the grain boundaries; here grains below 565 µm diameter were ignored by applying a filter.
What grain statistics were measured on the Styrofoam?
167 grains occupied 166.917 mm² (64.5962%) of the projected area, at 0.646285 grains/mm², with a mean area of 0.999500 ± 0.491846 mm² and an equivalent diameter of 1098.61 ± 256.235 µm.
What does 3D data add to boundary analysis?
With the 3D topography, the volume, height, peak, aspect ratio and general shape of each grain can be analyzed, beyond the 2D image analysis of conventional grain boundary imaging.
Why use a chromatic confocal profilometer for this study?
Using axial chromatism, it measures nearly any surface with no sample preparation and open staging for a wide range of sample sizes, from nano to macro range, with zero influence from reflectivity or absorption, high surface angle capability and no software manipulation of results.
Which NANOVEA instrument was used for surface boundary measurement?
The NANOVEA ST400 3D Non-Contact Profilometer.
