Magnetic nanoparticles used to develop polymers with a "memory"

(Nanowerk News) In a joint project with the German Institute of Polymers in Darmstadt, GKSS scientists from the Institute of Polymer Research in Teltow near Berlin have succeeded in developing polymers with a "memory". With the help of magnetic nanoparticles, it is possible to control the shape of these polymers, thus paving the way for exciting new applications in the field of medical technology.
The results of this research have now been published in an article titled "Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers" in the Feb. 28. 2006 online edition of Proceedings of the National Academy of Sciences.
Magnetically induced shape-memory effect of a polyetherurethane with embedded magnetic nanoparticles. Within 24 sec. the temporary fixed shape (rod) recovers into the original shape (spiral) inside of a magnetic field of an inductor ring. (Source: GKSS)
So-called shape-memory polymers have the ability to reassume their original shape following temporary deformation. This function can be activated by means of external stimuli such as an increase in ambient temperature. In collaboration with the German Institute of Polymers in Darmstadt, GKSS scientists from the Institute of Polymer Research in Teltow have now succeeded in developing a new controllable magnetic process that triggers the change in shape without the need for direct contact with the polymer.
This process works on the basis of magnetic nanoparticles of iron oxide. These are finely distributed in the polymer and convert the energy from a magnetic field into heat. A desired temperature can be set by varying the proportion of nanoparticles in the polymer and the strength of the magnetic field. The scientists from Teltow and Darmstadt see applications principally in the field of medical technology. For example, it will be possible to develop remotely controlled catheters.
"These catheters could be used to rinse, fill or drain organs or vessels without the need for extensive or painful surgery every time a modification to the therapy is required," says Professor Andreas Lendlein, Head of the Institute of Polymer Research at GKSS in Teltow.
Source: GKSS