EurekAlert  June 10, 2020
Silicon is very brittle which can become a problem when trying to make MEMS from silicon, such as the acceleration sensors in smartphones. Researchers in Switzerland have demonstrated that Si processed by modern lithography procedures exhibits an ultrahigh elastic strain limit, near ideal strength (shear strength ~4 GPa) and plastic deformation at the micron-scale, one order of magnitude larger than samples made using focused ion beams, due to superior surface quality. This extended elastic regime enables enhanced functional properties by allowing higher elastic strains to modify the band structure. Further, the micron-scale plasticity of Si allows the investigation of the intrinsic size effects and dislocation behavior in diamond-structured materials. The study demonstrates a surface engineering pathway for fabrication of more robust Si-based structures…read more. Open Access TECHNICAL ARTICLE
The pillars are first etched through a resist, then oxidized and finally cleaned. On the right, the result can be seen (electron microscope image). Credit: Illustration: ETH Zurich