3. Other Artifacts

3.3 Flying Tip

This artifact shows that the AFM is not properly tracking the surface.
In the example below the effect is obvious, but this is not always the case.
Sometimes it is clearer if you look at some of the other signals, like amplitude or phase or deflection images. In the images shown below, note how all the features have a "tail" to their left.

AFM image showing poor feedback

In the example above, the image of nanoparticles shows "tails" on each particle, to the left. The image was recorded scanning from right to left.Typically, the left to right image would show the tails on the right side of each feature. It is typical of this effect that you will get different images in the two directions.

How to avoid it.
If you see this, your feedback parameters are incorrect.
It is usually easy to fix. You generally should increase integral gain, then the proportional gain, you may need to change the setpoint too, or even scan more slowly. See the answer about adjusting AFM feedback parameters here, in in my book.

Where to buy: AFM Probes - Distributors


This page lists distributors (as oposed to manufacturers) of AFM and other SPM probes. Currently the list is (very) incomplete.


 The book, "Atomic Force Microscopy" by Peter Eaton and Paulbook cover  West was published in March 2010 by OUP.

There is some information about it at this site, but it's somewhat out of date. In particular the contents listing is not quite correct.

 Here is the correct contents of "Atomic Force Microscopy": 


Chapter 1: Introduction
1.1 Background to AFM
1.2 AFM today

Chapter 2: Instrumental Aspects of AFM
2.1 Basic concepts in AFM instrumentation
2.2 The AFM stage
2.3 AFM electronics
2.4 Acquisition software
2.5 AFM cantilevers and probes
2.6 AFM instrument environment
2.7 Scanning environment

Chapter 3: AFM Modes
3.1 Topographic modes
3.2 Nontopographic modes
3.3 Surface modification

Chapter 4: Measuring AFM Images
4.1 Sample preparation
4.2 Measuring contact mode images
4.3 Measuring intermittent contact mode images
4.4 High-resolution imaging
4.5 Force curves

Chapter 5: Image Processing in AFM
5.1 Processing AFM images
5.2 Displaying AFM images
5.3 Analysing AFM Images

Chapter 6: Image Artifacts in AFM
6.1 Probe artefacts
6.2 Scanner artefacts
6.3 Image processing artefacts
6.4 Vibration noise
6.5 Noise from other sources
6.6 Other artefacts

Chapter 7: Applications of AFM
7.1 AFM applications in materials science
7.2 AFM applications in nanotechnology
7.3 AFM applications in the life sciences
7.4 Industrial AFM applications

Appendix A: AFM Standards

Appendix B: Scanner Calibration and Certification Procedures

Appendix C: Third Party AFM Software





To buy the book, visit Amazon.com

AFM Artifacts


1.1 Tip-sample convolution


This is an inherent feature of AFM and can never be fully removed. Any AFM image is a convolution of the shape of the probe, and the shape of the sample. This has the effect of making protruding features appear wide, and holes appear smaller (both narrower and often less deep, too). Broader (less sharp) probes will enhance the effect, as shown below.



 Illustration of convolution of AFM probe and sample giving rise to the image (red).


Probe-sample convolution tends to have the greatest effect on features of similar or smaller radii than the probe. it can be reduced by deconvolution techniques, discussed further in "Atomic Force Microscopy".


I've recently updated the SPM software list, with a couple of new (to me) programs, Mountains and TrueMap. Both are based on profilometer software, but also offer to open AFM files. Since profilometry and AFM produce very similar data, this makes sense, and both are capable programs, though I found mountains more flexible in opening AFM file formats. However, since AFM and profilometry tend to be used for different samples, the requirements can be somewhat different, and most AFM-specific packages are more flexible in for example levelling procedures, which are very important. The links to the programs can be found on the software page.