Conductive polymer surfaces with carbon nanotubes - Fraunhofer IWS Dresden at the trade fair O&S in Stuttgart

Press release (Nr. VI) /

The Fraunhofer Institute for Material and Beam Technology IWS Dresden presents a newly developed method which allows the addition of an electrical surface conductivity to polymers during the production or processing in a shape tool.

Transparent PMMA disc with electrical surface
© Fraunhofer IWS Dresden
Transparent PMMA disc with electrical surface
Electroluminescence foil on the basis of CNT layers as transparent electrode
© Fraunhofer IWS Dresden
Electroluminescence foil on the basis of CNT layers as transparent electrode

A highly conductive network of carbon nanotubes (CNT) is integrated only a few nanometers in the polymer surface by using a facile process step. The applied method is acutely cost efficient, technically practicable and able to be integrate into existing industrial facilities. Compared with usual used conductive additives, which are added to the bulk polymer, the material cost are very low, because CNT layer with only a few nanometer thickness are necessary. To supply a surface of 1m² with a 50 nm thick CNT layer you only need a few milligrams of CNTs.

Next to the low price, the material savings have the advantage that the mechanical and optical properties of the polymer remain nearly unchanged. Furthermore, the high conductivities are also of advantage. With a conductivity higher than 10-9S materials are deemed to be not electrostatic chargeable and the conductivities reached with this method have a value of 10-3S, magnitudes higher.

The reached transparency and the high flexibility of the CNT network allow it to use these layers as transparent electrodes in conjunction with polymer foil for flexible optical devices like electroluminescence foils (see figure 2), for example.

This method has been demonstrated at the fair O&S in Stuttgart (8 – 10 June 2010) for the first time.