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Jena Researchers Boost AFM Sharpness with ‘Microwaved’ Tips

by Editor1 last modified October 26, 2010 - 13:20

Scientists from Germany’s Friedrich-Schiller-University in Jena are improving a fabrication process for Atomic Force Microscopy (AFM) probe tips. Rather than complex tasks of attaching nanoscale tips to the probes, chemists are growing tips directly on the probe.

Jena Researchers Boost AFM Sharpness with ‘Microwaved’ Tips

AFM uses nanoscale scanning probes, and the tips of those probes often determine the AFM image quality because the size and quality of the tips limit the dimensions that can be visualized – the smaller the probe, the smaller the structures that are revealed.

While carbon nanotubes can offer researchers great advantages, it is often difficult to attach them on scanning probes. To overcome these difficulties, a German research team led by Prof. Dr. Ulrich S. Schubert of the university’s Institute of Organic Chemistry and Macromolecular Chemistry has developed a new process that allows the growth of carbon nanotubes on the actual scanning probe.

Prof. Schubert’s team uses microwave radiation for a gentle but very fast growth of the nanotubes. The growth starts at small cobalt particles.

"The method we developed can potentially result in a very cost-efficient production technology of for instance high resolution probes for Scanning Force Microscopy,” Prof. Schubert said. “These are already available on the market but they are very expensive at 350 Euro each. With the process we can reach a price level, that would justify the use of such tips also just for routine measurements."

"Carbon nanotubes can be grown very quickly due to the special conditions inside of the microwave which can generate a pressure up to 20 bar" said team member Dr. Stephanie Hoeppener.  The metal particles strongly heat up in the microwave and reach a temperature that is sufficient to convert alcohol vapor into carbon. The heating process works similar like a forgotten spoon in the kitchen microwave which also absorbs the microwave radiation very effectively, according to Tamara Druzhinina, another Schubert team member.

CNTs can be grown very quickly due to the special conditions inside of the microwave which can generate a pressure up to 20 bar, according to the team’s research.

The work is published in the leading scientific journal for Nano Science, Nano Letters.