Mobile phone is allowed to being dropped in the future
FOM-doctoral student Paulette Prins has demonstrated that plastic is not as poor a conductor as the current semiconductors. This clears the way for a revolution in consumer electronics: just imagine, mobile phones and MP3-players that are 'survival-proof' when being dropped. On 20 March 2007 Prins will take her doctoral degree at the Delft University of Technology.
It would be a tremendous solution: consumer products that do not break if accidentally dropped: appliances that have flexible, or even rollable screens, and products that will also become a great deal cheaper. To the present day, this was still impracticable. The turning point in the development of appliances are the chips. For, they have to conduct an electric current and plastic chips are not very good conductors. Plastic conducts at least a thousand times worse than the current semiconductors.
Prins demonstrated that a purpose-made plastic will conduct just as well as existing semiconductors.
Chains
Conductivity occurs when an electric charge moves through the material. Prins discovered that the movement of charge in plastics is particularly impeded by the structure of the material. Plastic is built up from polymers, which consist of complex chains. The greater obstacles for conductivity appeared to be the ends of the chains, fractures in the chains, as well as the chaos in and along the chains.
A team of German researchers rebuilt the chains. They made a polymer with a relatively fixed, ladder-like structure. Prins made cleverly use of this. This polymer appeared to conduct a thousand times better than had previously been shown for plastics by experiment.
Technologies
The combination of simulations and advanced techniques makes Prins's research unique. She bombarded the material with electrons from a particle accelerator and that enabled her to study the fast reactions in the plastic accurate to one hundred microseconds.
Thereupon, she determined the conductivity of the polymers by measuring the microwave absorption. This enabled her to get around the use of electrodes that often disrupt measurements. Prins had their findings published in the leading scientific journal Physical Review Letters.
For more information, please contact:
Ir. Paulette Prins (Delft University of Technology), phone: +31 (0)15 278 39 14;
She defended her doctoral thesis on 20 March 2007 at the Delft University of Technology.
Supervisor: Professor L.D.A. Siebbeles