This project aims at the development of micromechanical and microoptical components made of pure synthetic crystalline diamond by exploiting a novel processing method, based on advanced microelectronics manufacturing technologies. The unique mechanical properties of diamond include extreme hardness and fracture strength as well as the highest known elastic modulus of any material, making it an extremely interesting material for novel components such as micromechanical gears, as for example used in mechanical watches.
Single crystal diamond (SCD) is an ideal material for mechanical watch parts due to its exceptional properties such as low weight, low friction between components, amagnetism and visual appeal. However, thick released SCD components are typically fabricated using laser cutting, which results in rough sidewalls and limited accuracy not adapted for mechanical watch parts.
This project aims to develop a manufacturing process based on microfabrication techniques to produce commercial SCD components of high precision and quality. In a first stage, we developed a fabrication process based on deep reactive ion etching of SCD using oxygen plasma with a thick Al-SiO2 multilayer hard mask and fabricated released 150 µm thick watch components. The sidewalls have a roughness better than 200 nm (rms) and sidewall angles of 82° to 93°. In a second stage follow-up project in collaboration with LakeDiamond SA, the fabrication process was optimized to increase the sidewall’s verticality, smoothness and process throughput, aiming to develop a commercial offering of diamond micromechanical parts for watches.
Example of diamond pieces for watch industry.
Process flow for the production of diamond mechanical pieces.
Publications
- Toros A., Kiss M., Graziosi T., Sattari H., Gallo P., and Quack N., 2018. Precision micro-mechanical components in single crystal diamond by deep reactive ion etching. Published in: Microsystems & Nanoengineering, vol. 4, no. 1, Dec. 2018. https://doi.org/10.1038/s41378-018-0014-5
- Quack N. , Toros A., Kiss M., Graziosi T. and Gallo P., Patent WO/2019/043432 “Single crystalline diamond part production method for stand alone single crystalline mechanical and optical component production”.
- Presentation by Marcell Kiss in Gothenburg, SE, at the
International Conference on Diamond and Carbon Materials (3-7 Sept 2017)
Funding
Stage 1
Gebert Rüf Stiftung, with support from LakeDiamond SA.
Starting date : 02.2017. Duration : 14 months
Stage 2
Innosuisse, collaboration with LakeDiamond SA.
Starting date : 04.2018. Duration : 18 months
