Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Manipulating complex molecules by hand

07.11.2014

New method in scanning probe microscopy: Jülich researchers create a word using 47 molecules

Jülich scientists have developed a new control technique for scanning probe microscopes that enables the user to manipulate large single molecules interactively using their hands. Until now, only simple and inflexibly programmed movements were possible.


A word with just 47 molecules

Copyright: Forschungszentrum Jülich


Entwined ways out: The molecules can be extracted by ‘peeling’ them from the layer, as shown by this image of the successful trajectories required to write 'JÜLICH'.

Copyright: Forschungszentrum Jülich

To test their method, the researchers "stencilled" a word into a molecular monolayer by removing 47 molecules. The process opens up new possibilities for the construction of molecular transistors and other nanocomponents. The findings have been published in the Beilstein Journal of Nanotechnology.

"The technique makes it possible for the first time to remove large organic molecules from associated structures and place them elsewhere in a controlled manner," explains Dr. Ruslan Temirov from Jülich's Peter Grünberg Institute.

This brings the scientists one step closer to finding a technology that will enable single molecules to be freely assembled to form complex structures. Research groups around the world are working on a modular system like this for nanotechnology, which is considered imperative for the development of novel, next-generation electronic components.

Using motion tracking, Temirov's young investigators group coupled the movements of an operator's hand directly to the scanning probe microscope. The tip of this microscope can be used to lift molecules and re-deposit them, much like a crane.

With a magnification of five hundred million to one, the relatively crude human movements are transferred to atomic dimensions. "A hand motion of five centimetres causes the sharp tip of the scanning probe microscope to move just one angstrom over the specimen. This corresponds to the typical magnitude of atomic radii and bond lengths in molecules," explains Ruslan Temirov.

Controlling the system in this way, however, requires some practice. "The first few attempts to remove a molecule took 40 minutes. Towards the end we needed only around 10 minutes," says Matthew Green. It took the PhD student four days in total to remove 47 molecules and thus stencil the word "JÜLICH" into a perylenetetracarboxylic acid dianhydride (PTCDA) monolayer.

PTCDA is an organic semiconductor that plays an important role in the development of organic electronics – a field that makes it possible to print flexible components or cheap disposable chips, for example, which is inconceivable with conventional silicon technology.

Small spelling mistakes can even be corrected without difficulty using the new method. A molecule removed by mistake when creating the horizontal line in "H" was easily replaced by Green using a new molecule that he removed from the edge of the layer. "And exactly this is the advantage of this method. The experimenter can intervene in the process and find a solution if a molecule is accidentally removed or if it unexpectedly jumps back to its original position," says the physicist.

The interactive approach makes it possible to manipulate molecules that are part of large associated structures in a controlled manner. In contrast to single atoms and molecules, the manipulation of which using scanning probe microscopes has long been routine, larger molecular assemblies were almost impossible to manipulate in a targeted manner until now.

The reason for this is that the bonding forces of the molecules, which are bound to all of the surrounding neighbouring molecules, are almost impossible to predict exactly. Only during the experiment it becomes clear what force is required to lift a molecule and via what path it can be successfully removed.

The experience gained will help to speed up time-consuming operations. "In future, self-learning computers will take over complex molecule manipulation. We are now gaining the intuition for nanomechanics that is so essential for this project using our novel control system and quite literally by hand," says Dr. Christian Wagner, who is also part of the Jülich group.


Original publication:

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope
Matthew F. B. Green, Taner Esat, Christian Wagner, Philipp Leinen, Alexander Grötsch, F. Stefan Tautz, Ruslan Temirov
Beilstein J. Nanotechnol. 2014, 5, 1926–1932, published 31 October 2014
DOI: 10.3762/bjnano.5.203

Animation: Manipulating a PTCDA molecule with the scanning probe microscope


noPlaybackVideo

DownloadVideo

The large PTCDA molecule has four reactive oxygen atoms at its corners. These bind the molecule to the tip of the scanning tunnelling microscope once it approaches closely enough.
Source: N. Fournier, C. Wagner, C. Weiss, R. Temirov, F.S.Tautz, Physical Review B, 84, 035435, 2011 (“Copyright by the American Physical Society”)

Further information:

Press release from 17 August 2012, "Force Meter for Molecular Bonds" (in German)

Research at the Peter Grünberg Institute – Functional Nanostructures at Surfaces (PGI-3)

Young investigators group "Complex Transport Regimes in Low-Temperature Scanning Tunnelling Microscopy" headed by Dr. Ruslan Temirov at PGI-3

Contact:

Dr. Ruslan Temirov
Peter Grünberg Institute – Functional Nanostructures at Surfaces (PGI-3)
Tel: +49 2461 61-3462
r.temirov@fz-juelich.de

Press contact:

Tobias Schlößer
Corporate Communications (UK)
Tel: +49 2461 61-4771
t.schloesser@fz-juelich.de

Tobias Schlößer | Forschungszentrum Jülich
Further information:
http://www.fz-juelich.de

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>