Smart glass and music from SLS

Every year the PSI Founder Fellowship Programme supports new ideas for innovative applications with up to 150,000 Swiss francs. Whether smart glass or music restoration at the synchrotron – the resulting spin-offs are as diverse as the research at PSI.

Glass is no modern invention – in fact, archaeological finds show that this material has been manufactured and used by humans for more than 5,000 years. Glass is not only used as a vessel for fine wines – optical lenses are also ground from glass to make the smallest or most distant objects visible. Our communications flow through glass fibres in optical cables. Windows keep out the wind and rain while letting light pass through. The translucent material finds application in numerous areas of our civilisation. Yet glass is not just glass – we adapt it to our needs and reinvent it more or less constantly.

Barbara Horvath works with glass. The materials scientist, a candidate for the PSI Founder Fellowship, has been working to establish her spin-off Inveel since August of this year. Using tiny nanowires, the young entrepreneur wants to print electrodes on glass, for example to change its optical and electrical properties.

Smart glass

“One possible application for our technology is socalled switchable glass – also called smart glass,” Horvath explains. “That is a special material that can turn opaque, transparent dark or coloured, automatically or at the touch of a button.” This capability is enabled by a thin nanostructured coating sandwiched between two panes of glass. When electrical charges are applied to this layer, it becomes optically active and can change its colour as a result. This not only puts privacy at your fingertips, but can also be used to regulate the temperature in buildings.

The invention itself is not new. Such glass is already in use for windows in modern office buildings and aircraft, for example. However, producing them is very complex and thus costly. “To be able to apply the weak electrical charges to the switchable glass, thin wires must be accommodated – so thin that they will not impair visibility,” Horvath explains.

During her work at PSI, Horvath and her group leader Helmut Schift developed a method for the production of such fine conductor tracks. “Our method makes it possible to produce wires with a diameter of around one hundred nanometres,” the scientist explains. It functions much like a printer: nanoparticles are applied as liquid droplets and fuse together to form linear structures. This allows large areas to be printed with extremely fine, parallel conductors. Using conductive materials such as silver and gold, a wide variety of surfaces can be furnished with invisible electronics quickly and inexpensively.

Switchable glass is just one possible application. The nanowires could also be used to change the direction of polarisation of incident light in the glass so that only certain wavelengths penetrate. This could be used, for example, for temperature control in greenhouses or for laser protection in eyeglasses. “In the laboratory, we have shown that the technology works in principle,” Horvath adds. “The Founder Fellowship has now made it possible for us to take the next step towards practical applications.”

Read more on PSI website

Image: Barbara Horvath wants to use thin nanowires to alter the optical and electrical properties of glass.

Credit: Paul Scherrer Institute/Markus Fischer