ImAFM Applications

Mapping mechanical parameters

By adjusting the parameters of a particular force model, we can fit the model to the data acquired at every pixel of the image.  The fitted parameter values can be plot as a color map, which can be projected on to the surface topography to make a 3D surface parameter map.  The software has a graphical user interface for generating color maps using a variety of different models.

The 3D surface parameter maps to the right show a step edge of a thin film of butylacrylate spin coated on a Si wafer.  The  van der Waals - DMT model was fit to the data by adjusting the parameters: E*- effective elastic modulus, Fad - adhesive force,  zpen - tip penetration in to the surface, and a0 - range of the van der Waals force.   Sample courtesy of Eva Malmström (KTH) and Henrik Hillborg (ABB).

Mechanical response of polymers

Parameter maps (described above) have been generated for a sample of low density polyethylene in polystyrene.  The data were fit to the same van der Waals - DMT model, however this time the interaction range a0 was fixed to 2.2 nm.  The polyethylene forms spherical domains which  are much softer and less adhesive than the surrounding polystyrene matrix.  The small sharp features in the lower part of the image are surface contaminants.  Sample courtesy of Peter de Wolfe  (Veeco corp). 

Multiple amplitude and phase images

With ImAFM you acquire multiple amplitude and phase images in one scan.  The ImAFM Software Suite allows you to quickly flip through the images so you can easily see where the interesting contrast is and further investigate these areas with the pixel and line inspector tools.

The images to the right are a selection of the 32 images acquired in one scan on a block copolymer sample.  The copolymer self-organizes in to an array of domains which can be seen in the amplitude and phase of the response at the frequency of drive 1.   The amplitude and phase at drive 2 and all the intermodulation products shows a much different and varying contrast.  Note that the signal-to-noise ratio is still quite good for intermodulation products near resonance of order 13, but the image at the second harmonic of drive 1 shows only noise.  Sample  courtesy of Detlef Knelbe (JPK Instruments). 

Force curves on soft polymers

You can instantaneously view the force curve at any point in your image and compare force curves from different image points with the pixel inspector.  The selected pixel is marked with an X which is color coded to the force distance curve in the pixel inspector frame.  No more guessing what is causing your image contrast.  It is quick an easy to get the actual calibrated force at every point of your image.

The image to the right is a polymer blend sample, showing a domain of low density polyethylene in polystyrene.  Sample  courtesy of Peter de Wolfe  (Veeco corp). 

click for larger image

Analyze transects

The line inspector is extremely powerful for analysis of features in your images.  With a simple click-and-drag you can collect and plot the response along an arbitrary transect.  This data set can be fit to a tip-surface force model and the parameters values along the transect are plotted in the line inspector frame.  The software remembers your plots along multiple transects, so it is easy to compare different force models along the same transect, or different transects with the same model.

The image to the right is a polymer blend sample, showing a domain of low density polyethylene in polystyrene.  Sample  courtesy of Peter de Wolfe  (Veeco corp). 

click for larger image

 Continue >>>