Analyzing ePTFE Membrane using the Nanosurf
easyScan 2 AFM
Nanosurf is a leading provider of easy-to-use atomic force
microscopes (AFM) and scanning tunneling microscopes (STM). Our products and
services are trusted by professionals worldwide to help them measure, analyze,
and present 3D surface information. Our microscopes excel through their compact
and elegant design, their easy handling, and their absolute reliability.
The abbreviation ePTFE stands for expanded polytetrafluorethylene, also known
as expanded Teflon. The mechanical and medical properties of the material depend
strongly on how the Teflon was expanded (mono- or bi-axially) and on the
resulting ePTFE network structures. Due to its inert properties inside a human
body, ePTFE is often used as an implant material. The empty spaces inside the
network structure encourage the growth of soft tissue into such implants, which
helps hold the implant in place quickly. There are many different ways to expand
PTFE, all leading to different network structures. It is therefore very
important to verify that the desired ePTFE structure was obtained after the
Analyzing ePTFE Membrane using the Nanosurf easyScan 2 AFM
In this application note, we analyzed an ePTFE membrane using the Nanosurf
easyScan 2 AFM. The topography image below clearly shows the intricate
network structure of the sample. The length of the fibers and the
size-distribution of the knots can conveniently be analyzed using the
measurement tools integrated in the Nanosurf
Compared to the conventional method used for this analysis — scanning
electron microscopy imaging, where a gold film must first be evaporated onto the
ePTFE sample in vacuum to make it conductive — AFM is much faster and easier to
perform. With the AFM, ePTFE can be measured directly, without any prior
treatment of the sample.
By choosing a grayscale color palette, AFM images can look very similar to
the SEM images that engineers in this field are used to. In contrast to SEM,
however, the AFM topography images contain quantitative depth information due to
the very nature of the recorded data.
ePTFE sample courtesy of Shanghai Suokang medical implants Co.
For more information on this source please visit Nanosurf