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 The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>