Atomic Force Blog

2011 Requimte AFM mini-course

2011-09-21T01:29:00.000-07:00

Requimte Hands-on Minicourse on Atomic Force Microscopy 2011

"Without any doubt I will recommend it for everybody which is interested in AFM" - 2011 student.

The 2011 edition of the AFM course was held between 14th and 16th september.

The students learned about:

AFM Background
AFM Instrumentation
AFM Modes - topographic and property modes
Sample Preparation
AFM Operation, with a section geared specifically towards the TTA-AFM, as well as general scanning instructions and hints and tips.
AFM applications
AFM Artifacts and troubleshooting AFM Operation
Data processing and Analysis
A guest lecture by Filomena Carvalho, from the IMM ( Faculty of medecine University of Lisob, on Force spectroscopy and biological aplications.
A second guest lecture by Rogerio Colaço of the IST, Technical University of Lisbon, about AFM applications in nanotribology

The course was very succesful, and some photos from the course, and images acquired by the students can be seen here.

Thanks very much to AFM Workshop for sponsoring the course!

AFM Manufacturers

2011-07-09T14:54:00.000-07:00

I've created a full list of manufacturers of Atomic Force Microscopes(AFMs) on AFMHelp.com. If there's anything missing, let me know!

It can be found here: Where to buy: AFM instruments

TTAFM Images

2011-04-01T04:00:00.000-07:00

Here are just a few example images measured with the new TTAFM instrument on a variety of samples.

Magnetic Force Microscopy

2011-03-03T04:27:00.000-08:00

Magnetic Force Microscopy
Magnetic force microscopy (MFM), is a family of techniques used to measure magnetic fields using an AFM. In fact there are a large number of different techniques used to measure magnetic properties, but in general, they all use the AFM to measure the oscillation of a magnetically sensitive probe when it is far (5-100 nm) from the sample surface. MFM probes are usually made by coating normal silicon probes with a thin magnetic coating. The magnetic coating means that the oscillation of the probe will change when in a magnetic field. However, when the probe is touching the sample, the short range tip-sample forces will obscure the magnetic forces (which are much weaker). Fortunately, since magnetic forces can be measured at a distance, it is possible to remove the probe from the surface, and still measure magnetic forces, while removing these short range forces. In order to make accurate measurements, the probe should be at the same distance from the sample throughout the image. There are a number of techniques to do this, which are reviewed in [1], but in most commercial implementations, the so-called “Lifting” method first used by Bard is used. This method is illustrated schematically below.

How MFM lifitng modes work

Read the rest of the article at afmhelp.com

Book available for review: Atomic Force Microscopy

2011-01-17T02:41:00.000-08:00

If you can write a review of my book for "Microscopy and Analysis" , you could get your review published in print, and keep a copy of the book! See below, and follow the link for details.

NEW! Book available for review: Atomic Force Microscopy

28 April 2010

This book will demystify AFM for the reader, making it easy to understand, and to use. It is written by authors who together have more than 30 years experience in the design, construction and use of AFMs and will explain why the microscopes are made the way they are, how they should be used, what data they can produce, and what can be done with the data. Illustrative examples from the physical sciences, materials science, life sciences, nanotechnology and industry illustrate the different capabilities of the technique.

Phase Imaging in AFM

2010-10-12T07:54:00.000-07:00

There is some confusion about phase imaging. Phase imaging is not really an operation mode in itself. It is carried out in intermittent contact mode (IC-AFM). In commercial AFMs. depending on the instrument, IC-AFM may be referred to as AC-AFM, vibrating mode, tapping, etc. If you carry out IC-AFM and monitor the phase signal, you are doing what is referred to as "phase imaging", i.e. generating a phase-contrast AFM image. Further confusion can occur because of the unrelated optical microscopy technique "phase contrast microscopy". There is also a technique in TEM called "phase-contrast imaging". Even more confusingly, with heterogeneous materials samples, researchers often refer to the different materials in the sample as forming different phases. Thus, many users are confused about what phase imaging in AFM really is. However, it is a powerful technique, for producing contrast on heterogeneous samples. In this shortened extract from Atomic Force Microscopy. The origin of the signal and its use is described in this article at AFMHelp.com.

Best SPM Image at IMC17

2010-09-30T08:10:00.000-07:00

At the 17th International Microscopy Congress (IMC17) in Rio de Janeiro, I won the 1st place prizee for best SPM image (Life Sciences). The collage of the winners is shown below. Once again, thanks to Gonçalo Dória for providing the sample.

Also at the conference, both Maria Feio and Ana Pereira gave excellent and well-received oral presentations, featuring AFM images obtained in our lab. Well done to both of them!

A new kind of AFM

2010-06-21T08:10:00.000-07:00

I have just built my first AFM. It was an amazing experience to actually put together the kind of instrument I've been using for ten years. When I actually began to scan with it it was amazing. This is a completely new kind of AFM; one that be assembled by anyone, and sells for a small fraction of the price of any other commercial AFM. I did not have a chance to fully characterise the performance, but from what tests I did, it could be very good indeed. If so, it opens AFM to a whole new range of users, who have access to small research budgets, but cannot afford "large" investment of 100,000 euros or so that a "normal" research-grade AFM costs.
This instrument is also very nicely designed to allow very linear operation, and it has sofware which is very easy to modifiy, as well as full documentation, making this a very flexible sintrument.
I am looking forward to playing with it more soon!

New AFM book released now

2010-04-21T09:24:00.000-07:00

My book, Atomic Force Microscopy, by Peter Eaton and Paul West is now available for order from OUP or amazon.co.uk. It has tons of background information, like how AFMs are built, and how the modes work, but also practical information like how to carry out AFM imaging, from sample preparation to image processing, how to analyse the images, and how to avoid AFM artifacts.
The applications chapter covers nanotechnology, physical science, biology and industrial applications. Detailed application examples were chosen specifically to illustrate the range of capabilities of AFM. Appendices include SPM probes, SPM calibration standards, and calibration procedures. The book is aimed particularly at researchers using AFM, and students on course covering SPM techniques (especially nano-sciences courses).

Free AFM Chapter

2010-03-19T09:27:00.000-07:00

There is a freely-downloadable .pdf (4.8 MB file) of chapter 1 of my book, "Atomic Force Microscopy" available on the OUP web site. This has the preface and the whole of chapter 1.

This chapter contains background to AFM, and describes a few of the capabilities of the technique It explains how the technique was invented, and which instruments preceded it, and why AFM was needed. It also compares AFM to other microscopy techniques. The preface also contains information of the contents of the rest of the book.

The book should be published around 25th of March, in just a week now!

All Diamond AFM Tips

2010-03-04T02:09:00.001-08:00

I recently had the chance to try out some new AFM probes. They were "SCD" -single crystal diamond probes from Mikromasch. They are made by attaching a pyramidal diamond crystal to the end of a standard silicon lever. If you look at this paper, you can see some details of how they make them. The amazing thing to me is that the tips are attached to the cantilevers by GLUEING! Mikromasch must have some pretty careful guys, and a good micromanipulator there to do this reproducibly, because The levers are only about 30 microns across. And all the probes I tried were great.

I absolutely love these new probes. They just do not break. This makes it much easier to scan a whole bunch of samples with the same probe, without changing half way through, or finding image quality degrading towards the end of the batch. The next batch of probes I order will be these ones. If anything, these might be a poor commercial proposition, because I will order far fewer of these, since they last much longer. I am keeping one probe to use for each project! Of course, apart from breaking, it’s possible to mess up your probes by contamination, so you still have to be careful with them.

NOTE: I believe several other companies also offer similar products, though I have not tried them - Check out the list of probe manufacturers here.

UPDATE: Apparently I was right to think that producing these reliabliy is difficult, becasu eat the moemnt they are out of stock. Hopefully they will fix the production problems soon!

NOTE: Image comes from http://www.spmtips.com

SPMage 09 Gallery Online

2010-03-02T05:41:00.000-08:00

The results from the SPMage09 AFM image competition have been put online. You can see them here. Congratulations, in particular to Ana, Filomena and Rachel, who produced these fantastic images. Images reproduced from the SPMage website.

Available for pre-order

2010-01-29T06:37:00.000-08:00

I noticed today that as well as the OUP site, my book, "Atomic Force Microscopy" is now available for pre-order at amazon. I have not idea why, but it seems to be due out in amazon.co.uk
in March, but at amazon.com
only in May 2010. I am excited, and hope it does really well!

For more details on what's in the book, look at afmhelp.com.

Looking For Lunch

2010-01-28T08:07:00.000-08:00

One of our AFM images (measured by Cristina Neves and I) was featured in the Veeco SPM 2010 calendar - the image shows a malarial mosquito eye - the image was named "Looking for Lunch" by Veeco:

Multimode and ease of use

2010-01-14T08:11:00.000-08:00

I just noticed that late last year, Veeco launched the "Multimode 8", the eighth version of the most popular research AFM in the world. As far as I know, hardware-wise they are pretty much the same as the Nanoscope 3, what's really changed is the software, and their ability to use new modes. One the innovations, this time is what Veeco calls "ScanAsyst"(TM Veeco). This is a routine that is designed to constantly monitor the images recorded, and adjust feedback settings to improve image quality.
I have not seen it in action, but if it works, it should be a good thing. Feedback adjustment routines have been tried before, and apparently were not very popular, but it is important that AFM becomes easier to use. At the moment, the problems for AFM are:
1. People don't understand it.
2. It's hard to use.
3. The probes are unreliable, and break/get dirty often
4. It's slow.

Hopefully my forthcoming book "Atomic Force Microscopy" will help with part one. Manufacturers of instruments can, and are, trying to address points 2 and 4 (see also fast AFMs, and self-aligning optics from Asylum). The quality of probes can be improved, but it's hard to stop them getting contaminated. On the other hand, the new diamond probes do break less often...
Will we soon see a time when AFM is a routine technique?

SPMage Partial Results

2009-10-26T08:42:00.000-07:00

The winning images of the SPMage09 posts have been revealed, and the winners include some really nice images. However, for many months, the website has said, "The full set of finalist images of the SPMAGE09 contest will be available at this web site soon." This was supposed to occur in June 2009! Hopefully the full list will be posted in the near future.

UPDATE: The website seems to have removed the "will appear soon"..I guess they gave up on the idea of publishing the shortlist...
images taken from, and copyright Spmage09 competition.

AFM Book Contents

2009-10-11T08:02:00.000-07:00

The book, "Atomic Force Microscopy" by Peter Eaton and Paul West will be published in March 2010. The 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 chapter list for "Atomic Force Microscopy":

Preface

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 artifacts
6.2 Scanner artifacts
6.3 Image processing artifacts
6.4 Vibration noise
6.5 Noise from other sources
6.6 Other artifacts

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

Index

New AFM Book

2009-09-03T02:17:00.001-07:00

I have written a book about AFM. It was written in collaboration with Paul West, founder of Topometrix and Pacific Nanotechnology, and currently consulting at the AFM division of Agilent. The title of the book is "Atomic Force Microscopy" - simple, eh? The idea is to simplify AFM, and make it accessible for the new user or student. It covers theory AND practice, specifically instrument design, use of the AFM, and interpretation of the data. I will write some more about the content at a later date, but in the meantime a new website has been set-up to accompany the book, with updated, and additional information from it. It's at: http://afmhelp.com. You can find the publisher's description of the book by clicking here.

Funding of Science in Portugal

2009-06-04T03:29:00.001-07:00

I found out something about how science is funded here in Portugal, today. Working in the physical sciences in Portugal, we basically have one source of funding: the FCT. Now, the way they assign funding to associate laboratories, like the one I work in is based on the number of people working here, and the number of publications we produce. So far, so good, we should be rewarded for publication. I suppose only peer-reviewed publications count, which is understandable. The journal are assessed based on the impact factor. This relates directly to the amount of money we'll get to carry out resarch. And it's not a lot of money, so we need all we can.
OK, I don't like only journals counting (what about books?), and I don't like journal imact factors as a way to judge the merit of a paper, but this is a system that's no worse than many.

But here's the stupid bit: each publication is assessed based on the impact factor of the jounal in the year in which it was published.

In other words, the ONLY criteria we should choose where to publish by is current impact factor. And new journals, that don't have an impact factor yet published, even from the Public Library of science, or ACS, or, for that matter, Nature, are worth NOTHING.
If anyone can explain to me why this is a good thing, I'll be happy. Surely the FCT want to encourage us to promote our work? Why then do we get more for publishing in obscure journals, than for publishing in relevant, widely-read ones?

Another google knol article - SPM Standards

2009-05-04T13:40:00.000-07:00

I made a new knol, all about SPM stnadards.
Standard samples are important to enable proper calibration of the AFM, as well as to characterise tips, and are also usfeul to test imaging conditions, new modes, etc.
The knol is here:
http://knol.google.com/k/peter-eaton/spm-standards/25laaiqlcn2x8/6#
In the article I link to suppliers of x-y, z, probe tip, phase, LFM and biological standards.
If you know of any I missed, please let me know!

AFM Image Competition

2009-02-18T07:08:00.000-08:00

An AFM image competition is open from Nanotec, you can find the rules, and enter here. The competition is open to any SPM image, and in the last edition, the standard was very high. There were some really beautiful images, so go take a look at the gallery. We got a shortlist place last year, with a blood-cell image from Joaõ Fernandes (shown below). Enter by 1st March, stand a chance of winning 5000 Euros.

AFM Software Knol

2008-11-04T09:09:00.001-08:00

I created another google knol, this time about AFM (and STM software) find it here. I am trying to maintain this list updated, and make it comprehensive, so please add any software i missed out.

2008-08-05T06:40:00.000-07:00

I have created a knol on AFM. Knol is a new site from Google intended to carry authoritative articles on specific topics. It's been reported as a rival to Wikipedia, but it's different. Google's idea is that articles will be open to collaboration, but will be more easily controlled, so that articles become authoratative. Also, you can see the credentials and identity of the authors more easily.
Here's the address:http://knol.google.com/k/peter-eaton/atomic-force-microscopy-afm/25laaiqlcn2x8/3#

DNA -Nanoparticle interactions

2008-01-31T00:43:00.000-08:00

I recently had 2 communications published on AFM of the intereaction of gold nanoparticle with DNA. You can find them at: IEEE transaction on NanoBioscience, and if not there, the papers can be downloaded from my publications page.

AFM, unlike any other microscopy technique lets us see the metallic nanoparticles AND the DNA. In the image below, the particles are hybridising to a specific gene sequence.

This kind of image lets us see directly if the particles are correctly recognising the gene in question. In this case, it's associated with the blood disease beta-thalassemia. The gold particles here have detected that the patient did not have the disease. The aim of the work is to enable aquick and simple genetic screening procedure, as the binding of the nanoparticles also causes a colour change in solution.

Linearised scanners, at last!

2007-02-13T06:21:00.000-08:00

I went to Lisbon last week, to try out a new AFM, the JPK Nanowizard II. For me, this was very interesting, as it's the first instrument I've used with fully linearised scanners This means, that unlike normal AFMs, when you tell it to scan in a particular place, it just does. With most instruments, if you ask it to move, say 6 microns right, and 2 down, it ends up going 6.9 right, and 1.5 down. Now, you can just pick an area and scan there. It also compensates, for other nonlinearities of scanners, that can distort your images. Of course, all this does not come for frre, the linearisation reduces overall resolution, and adds a little noise. But, you can always turn it off. AFMs should always have been like this!

Frequently Asked Questions about AFM

2007-01-31T05:29:00.000-08:00

I've created a FAQ on AFM, and SPM techniques. It is basically a list of the questions I get asked all the time, especially by "clients", it covers the background to AFM (very briefly), sample preparation, different AFM modes, a bit on data analysis and just a few points on running the AFM.
You can find it at:
http://www.fc.up.pt/pessoas/peter.eaton/afm_faq.html
Pete.

Open Access to EU funded Research?

2007-01-31T03:06:00.000-08:00

I recently was sent a link to a petition for the EU to mandate open access to research it funds.
This is a good idea, and it basically follows what already happens in the states. however, the NIH has created PubMed Central, to facilitate this. The EU needs an equivalent, if this proposal is to work.
When this started, many people thought it would lead to loss of revenue for the journals, and discourage authors from publishing their work. This has not been the case.
Publishers are not really opposed to posting works to print archives, as shown by the fact that many are already allowing authors to use them. Elsevier, the worlds largest publisher, issued a Statement to this effect.So, if you want to see open access to science, and who doesn't, sign the petition!
Pete.

1st Blog

2007-01-30T01:24:00.000-08:00

Hi, Welcome to the Atomic Force Blog. Here I plan to talk about my work, which is basically making measurements with the Atomic Force Microscope(AFM). So, it should be mostly about AFM, and my experiences with it. But not all.
Pete.