Touchscreens work because of the wafer-thin electrode under the glass display made of indium-tin-oxide (ITO). This material is excellent at conducting and lets the colors of the display pass through unhindered, making it ideal for touchscreen technology. However, indium is rare and expensive.
Alternatives to ITO are being sought at the Fraunhofer Institute, Germany, where a dual layer electrode is being developed. One layer is made of polyethylenterephthalate (PET), the other is made of a mixture of carbon nanotubes and electrically conducting polymers. This is applied to the PET as a solution and forms a thin film when it dries.
The carbon nanotubes create a network where the electrically conducting polymers can be firmly anchored, increasing durability. The electrical conductivity of the system is lower than that of ITO, but it is sufficient for application in electrical systems. More importantly, the polymer-based electrode is cheap and can be made from renewable resources.
Image: (c) Fraunhofer Institute
- The touchscreens containing carbon nanotubes will be presented at the nano tech 2011 fair in Tokyo (Hall 5, Stand E-18-11) from February 16-18.
- Fraunhofer Institute, Germany