An important condition for successful research in the field of nanotechnology is the availability of the most up-to-date equipment for analysis and synthesis on the nanometer scale. This is the reason why the Empa is constantly extending its range of instruments, which are used to investigate and process materials at the micro and nano level in very innovative ways.

Two such devices are currently sharing the limelight; a scanning force microscope that will enable researchers to identify atomic structures and surfaces, and an embossing system that allows the surfaces of individual fibers to be given a defined structure.

In Prof. Hans Josef Hug’s Surfaces, Coatings and Magnetism Laboratory at the Empa, a new scanning force microscope, or SFM, is being constructed. Based on a design developed by Prof. Hug at the University of Basel, the new instrument operates under ultra-high vacuum (UHV) and at a very low temperature (LT), only a few degrees above absolute zero. The predecessor instrument was used in Basel in 2001 to measure, for the first time, the force acting between two individual atoms. A very fine pointed tip, integrated into a micro-fabricated flexible cantilever, is positioned over a selected atom and slowly brought nearer to it. The force due to chemical binding which acts between the atom at the tip of the point and the sample atom can then be measured, and this provides information about the local chemical reactivity of a surface.

The new UHV-LTSFM scanning force microscope is being designed and constructed by physicists and mechanical engineers from Empa together with Prof-Hug’s coworkers from Basel. It will be much more sensitive than the previous instrument developed in 2001, thanks to its ultra small cantilever.

This will allow single molecules for example not just to be imaged, but even make it possible to observe their vibrational state. Further experiments of vital importance to fundamental research will also become possible. With the new SFM scientists will be able to manipulate materials on the atomic scale, and to create nanostructures from individual atoms or molecules.

Structured surfaces improve fibers and textiles

The properties of functional textiles are frequently dependent on the particular surface structure of the synthetic fibers used to make them. The structure is imparted to the fiber surface as it is spun and for technical reasons it has only been possible up till now to create structures along the length of the fibers. A team from the Empa in St. Gall led by Marcel Halbeisen, in collaboration with the Paul Scherrer Institute (PSI), has now developed an instrument which allows fibers to be given a transverse structure. At the moment only micro-scale structures have been embossed on fibers, but nano scale structures will also be possible in future.

A sophisticated system ensures that the embossed structure covers practically the complete fiber surface.

Depending on the pattern used, particular color and shimmer effects can be produced, and textiles can be created which, thanks to a special capillary structure, can not only absorb large quantities of liquid, but are also quick-drying. The process can be used to produce fibers which, due to their improved adhesion, help increase the tensile strength of concrete. Other embossed patterns encourage cell growth or render materials self-cleaning by virtue of the lotus effect. There might even be a commercial application of interest to manufacturers of brand-name articles: structured fibers woven into their products would make them practically impossible to counterfeit, since they could be then unambiguously distinguished from cheaper copies.

Master’s degree course in Micro und Nanotechnology

In order that the newest results from micro und nanoscience can be applied in the wider world as quickly as possible, the Empa is playing a leading role in an influential international network devoted to appropriate technology transfer. In combination with educational authorities and private companies, the Empa has begun this task by launching a further education course: the first product of the Micro- und Nanotechnology Network, or MNT, of the Lake Constance Region part-time master’s degree course. Students on the first course will begin work in October 2004.

For more information see http://www.fhv.at/edu/ce/mnt/.

«Nanotechnology» research program: Walter Muster, Tel. +41 44 823 41 20, E-mail: walter.muster@empa.ch

More information on the content of the research program is available at http://www.empa.ch/nanotechnologie or from the English language brochure «Materials Design in the Nanometer Range», which you can order from Rosemarie Lacher, Tel. +41 44 823 42 20, E-mail: rosemarie.lacher@empa.ch

Martina Peter, Communication/Marketing Dept., Tel. +41 44 823 49 87, E-mail: martina.peter@empa.ch