Developments in Atomic Force Microscopy - High Speed AFM

5 Developments in Atomic Force Microscopy — High Speed AFM 

Recently a new type of AFM, the VideoAFM , has been developed which by-passes many of the problems that have previously limited the AFM scan speed [5]. Images can be obtained in tens of milliseconds, compared to tens of seconds. This opens up the possibility of in-situ observation of crystallization with sub-lamellar resolution at timescales more than 1000 times shorter than those previously obtained. To-date this has been applied to the crystallization of polyethylene oxide at temperatures where growth rates of 100s of nm/s are observed [34]. 

Clearly there are many issues stiff to be addressed with the instrumentation of the VideoAFM to allow it to become a routine tool for the study of polymer crystallization. Not least is the need for image contrast mechanisms based on material properties, so that molten and crystalline areas can be clearly discerned. Also, there is a need to control the interaction force between the tip and the sample so as to allow more delicate samples to be imaged in a reproducible and non-destructive manner. However, the technique is already starting to provide new insights into the processes of crystallization and melting, and provides a route for considerable advances in the future. 

I have given a brief overview of some recent work on the application of in-situ AFM to polymer crystallization. The abihty to directly visualise the process continues to show unexpected behaviours and provide impetus for new directions in our exploration of this intriguing area of polymer science. 

One of my initial expectations in starting this work was that it would be possible to observe directly whether crystallization did indeed occur through intermediate states. Here this issue has been discussed in the context of recent 

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