Microengineering of diamond

Performance of micromechanical systems often relies on extreme material properties. Being the strongest, stiffest and hardest of all materials, exhibiting extreme electromagnetic transparency and wear resistance, and offering the highest possible thermal conductivity and very low friction against most materials, diamond is indeed a unique material. This unsurpassed combination of properties makes diamond a promising candidate in future microstructure technology.Microengineering of diamond has until recently not been possible due to its extreme hardness. However, the development of chemical vapour deposition (CVD) of diamond has opened up new possibilities in this field. Tools and substrate materials can now be coated with a thin layer of polycrystalline diamond, thereby enabling flexible and cost effective production of diamond microcomponents. Thus, diamond'smany unique properties can be exploited in numerous new applications. Several new techniques to shape diamond have been developed, e.g. replication of diamond in a mould, selective deposition, laser ablation, and plasma etching.The aim of the work presented in this thesis was to further develop and improve Microengineering of diamond and demonstrate a number of applications where diamond components could be highly useful. The possibility to create complex microstructures by replication of diamond in silicon moulds is investigated and improved. The possibility to alter and control the wetting abilities of diamondsurfaces, which is essential for many fluidic applications, is explored.Diamond microfluidic channels and systems are made and subsequently tested in biochemical applications like fast liquid chromatography. In another study, diamond's low adhesion and high wear resistance is verified and tested in transfer moulding of abrasive polymer compounds. Furthermore, devices such as diamond coated face seals exhibiting extremely low friction and wear as well as diamond abrasive tips for grinding and shaping hard materials are developed. Finally, a method for mass production of diamond microcomponents is demonstrated, taking Microengineering of diamond further towards the eagerly awaited commercial realisation.