Featured Research

from universities, journals, and other organizations

Radically better smarphones may be possible using system inspired by bird migration: Molecular chains hypersensitive to magnetic fields

Date:
July 5, 2013
Source:
Eindhoven University of Technology
Summary:
Researchers have for the first time created perfect one-dimensional molecular wires of which the electrical conductivity can almost entirely be suppressed by a weak magnetic field at room temperature. The underlying mechanism is possibly closely related to the biological compass used by some migratory birds. This spectacular discovery may lead to radically new magnetic field sensors, for smartphones for example.

Zeolite L is an electrically insulating aluminosilicate crystalline system, which consists of many channels running through the whole crystal and oriented parallel to the cylinder axis. The geometrical constraints of the zeolite host structure allow for the formation of one-dimensional chains of highly uniaxially oriented molecules.
Credit: MESA+

Researchers of MESA+, the research institute for nanotechnology of the University of Twente, in cooperation with researchers of the University of Strasbourg and Eindhoven University of Technology, are the first to successfully create perfect one-dimensional molecular wires of which the electrical conductivity can almost entirely be suppressed by a weak magnetic field at room temperature. The underlying mechanism is possibly closely related to the biological compass used by some migratory birds to find their bearings in the geomagnetic field. This spectacular discovery may lead to radically new magnetic field sensors, for smartphones for example.

The scientific journal Science publishes the research results on 4 July.

In their experiments, the researchers made use of DXP, the organic molecule which is a red dye of the same type as once used by Ferrari for their famous Testarossa. In order to thread the molecules so that they form one-dimensional chains of 30 to 100 nanometers in length -- 1 nanometer being 1 billionth of a meter -- they applied a smart trick: they locked the molecules in zeolite crystals. Zeolites are porous minerals composed of silicon, aluminum and oxygen atoms with narrow channels, like the lift shafts in a block of flats. The diameter of the channels in the zeolites is only 1 nanometer, just a little wider than the molecule's diameter. This enabled the researchers to create chains of aligned molecules inside the zeolite channel, which are only 1 molecule wide.

Molecular electric wires

The zeolite crystals containing the molecular wires were then placed on an electricity-conductive substrate. By placing a very sharp conductive needle, of an atomic force microscope (AFM), on top of a zeolite crystal, the researchers were able to measure the electrical conductivity in the molecule chains. Professor Wilfred van der Wiel, who developed and led the experiment, says that measuring the electrical conductivity in these molecular electric wires is a unique result in itself. "But the behavior of these wires is simply spectacular when applying a magnetic field," he adds. This is because electrical conductivity nearly completely breaks down in a magnetic field of just a few milliteslas in size, a field which you could easily generate with a refrigerator magnet. Van der Wiel: "The fact that the effect is so dramatic and occurs even in small magnetic fields at room temperature makes this result very special."

Single-lane road

The change in electrical resistance through a magnetic field is called magnetoresistance and is very important in technology. It is also used in hard disk read heads. Usually, magnetic materials are indispensable for creating magnetoresistance. However, the ultra-high magnetoresistance which has been measured in Twente was achieved without any magnetic materials. The researchers ascribe this effect to the interaction between the electrons carrying electricity and the magnetic field which is generated by the surrounding atomic nuclei in the organic molecules. Current suppression in a small magnetic field can ultimately be traced back to the famous Pauli exclusion principle, the quantum mechanical principle that states that no two electrons (fermions) may have identical quantum numbers. Since the electric wires are essentially one-dimensional, the effect of the Pauli exclusion principle is dramatic, comparable to an accident on a single-lane road that brings traffic to a standstill. This interpretation is supported by calculations.

Migratory birds

The mechanism that is responsible for ultra-high magnetoresistance in molecular wires is possibly closely related to the biological compass used by some migratory birds to find their bearings in the geomagnetic field. Researchers of the University of Twente are conducting follow-up experiments in the hope to be able to shed more light on this analogy.


Story Source:

The above story is based on materials provided by Eindhoven University of Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. N. Mahato, H. Lulf, M. H. Siekman, S. P. Kersten, P. A. Bobbert, M. P. de Jong, L. De Cola, W. G. van der Wiel. Ultrahigh Magnetoresistance at Room Temperature in Molecular Wires. Science, 2013; DOI: 10.1126/science.1237242

Cite This Page:

Eindhoven University of Technology. "Radically better smarphones may be possible using system inspired by bird migration: Molecular chains hypersensitive to magnetic fields." ScienceDaily. ScienceDaily, 5 July 2013. <www.sciencedaily.com/releases/2013/07/130705102059.htm>.
Eindhoven University of Technology. (2013, July 5). Radically better smarphones may be possible using system inspired by bird migration: Molecular chains hypersensitive to magnetic fields. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2013/07/130705102059.htm
Eindhoven University of Technology. "Radically better smarphones may be possible using system inspired by bird migration: Molecular chains hypersensitive to magnetic fields." ScienceDaily. www.sciencedaily.com/releases/2013/07/130705102059.htm (accessed September 16, 2014).

Share This



More Matter & Energy News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins