Researchers at the Universities of Queensland and New South Wales in Australia have discovered that the ability of a plastic to conduct electricity can be tuned by exposure to an ion beam. Usually plastics conduct electricity so poorly that they are used as the insulation around electrical cables.
However, the team was able to tune the properties of a plastic film using an ion beam so that it conducted electricity like the metals used in the electrical wires themselves – and even passed electric current without resistance, materials which do this are known as superconductors.
To demonstrate a potential application of this low-cost, robust, and flexible material, the team produced electrical resistance thermometers that meet industrial standards. These results are published in the journal ChemPhysChem.
Ion beam techniques are widely used in the microelectronics industry to tailor the conductivity of semiconductors such as silicon. Attempts have been made to adapt this process to plastic films since the 1980s, with limited success. While the use of argon and krypton ion beams leads to a substantial increase in electrical conductivity, the resulting films remain insulators.
The team took an alternative approach, known as ion beam metal-mixing, where a thin film of metal is deposited on a plastic sheet and mixed into the polymer surface using an ion beam. They found that this can produce conducting plastics with metallic or even superconducting properties.
"The process allows us to cover over ten orders of magnitude in electrical resistance and access three distinct regimes of conductivity – insulator, metal and superconductor – with a single material system", says Andrew P. Stephenson, lead author of the paper. This remarkable tunability is achieved by a careful choice of the species used for the ion beam. Stephenson and colleagues start with a polyetheretherketone (PEEK) film coated with a nanoscale layer of tin-antimony alloy, and use a tin ion beam to mix the metal into the plastic surface.
This results in an efficient and stable blending of the metal-polymer surface. Furthermore, the conductivity of the resulting material can be tailored precisely by tuning the initial metal film thickness, beam energy and beam dose.
This level of tunability and control in electrical resistance lends itself naturally to the application of resistance temperature measurement. As a demonstration of this potential application, the team tested their films against an industry standard platinum resistance thermometer, obtaining comparable accuracy. As well as being inexpensive, flexible and easily produced with equipment commonly used in the microelectronics industry, these materials are vastly more tolerant of exposure to oxygen compared to standard semiconducting polymers such as polyhexylthiophene or pentacene. "Combined, these advantages may give ion-beam-processed polymer films a bright future in the on-going development of soft materials for plastic electronics applications –a fusion between current and next-generation technology", the researchers say.
Author: Andrew P. Stephenson, Ben J. Powell, University of Queensland, Brisbane (Australia), http://www.uq.edu.au/
Title: A Tunable Metal-Organic Resistance Thermometer
ChemPhysChem 2011, 12, No. 1, Permalink to the article: http://dx.doi.org/10.1002/cphc.201000762
Andrew P. Stephenson | Wiley-VCH
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News