Nanocrystalline Diamond and Microengineered Diamond Components

Nanotechnology offers the potential for the creation of new products, but also the possibility to upgrade conventional technologies. As nanotechnologies become increasingly embedded in products and processes, their integration with the micro-scale is becoming critically important. This has many challenges both in understanding the fundamental scientific principles that underlie the integration, and also in the industrial realisation of components that exploit nanoscale phenomena. As an example, nanocrystalline diamond layers grown by CVD on appropriate substrates—silicon single crystals—combine the remarkable properties of conventional diamond, such as extreme hardness and wear resistance, a surface roughness in the range of a few nanometers and a negligibly small coefficient of friction of about 1 %. The films and layers consist of ultra small equiaxed grains of typically ~10 nm diameter with a semi-transparent appearance and a remarkable stability up to elevated temperatures. As such, they exhibit a considerably improved lifetime and reliability of tooling components and others. Moreover, by a sophisticated combination of photolithographic techniques and efficient reactive ion etching (RIE) processes established in microelectronics and silicon based microfabrication complex shaped diamond microparts and components can be designed and fabricated. A number of different applications, such as high precision lubrication- and wear-free microcomponents, micromechanical sensors and bio-applications are discussed.