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Laboratory for Mechanics of Materials & Nanostructures
We investigate mechanical materials properties from the nano to macro-scale using experimental, analytical, and computational techniques. Current cutting edge research within European projects and the ETH competence center on high temperature materials focuses on micro- and nano- mechanical properties of materials (instrumentation, scale effects related to microstructure and physical dimension. For this purpose, we (a) develop metallic model materials either via electrodeposition in combination with UV- and electron beam lithography, nanoporous membranes and via focused electron or ion beam processing and (b) push resolution frontiers of materials microanalysis instrumentation, for instance of glow discharge based surface depth profiling and tip enhanced micro-Raman spectroscopy. We focus on solutions for Swiss SMEs to increase mechanical reliability, production efficiency, and lifespan of new materials and systems ranging from thin films, watch parts and solar cells to power plant components.
Materials Mechanics and Nanomechanics
Macroscopically mechanical properties are dominated by a statistical distribution of defects with characteristic length scales like size and distribution of flaws in brittle fracture (100mm), or dislocation interdistance in metal plasticity (100nm). As dimensions are scaled down below the characteristic length, material properties become controlled by geometrical constraints. This includes physical device dimensions as well as microstructure length scales like grain size.
Nanostructuring of metals
Conventional optical lithographic techniques that form the basis of integrated-circuit chip fabrication can already be used to create sub-100 nm features, but requires huge investments. We explore new nanostructuring strategies for metals based on electrochemical and charged particle beam lithography techniques. On the one hand, electron and ion beam induced deposition is an attractive nanofabrication tool due to its capability of depositing structures of metallic material with nanoscale control of both size and placement.
Novel research in nanomechanics and nanostructuring requires specialised instrumentation, not all of which is available commercially. The microanalysis group within the Laboratory for Mechanics of Materials and Nanostructures has
- glow discharge instruments which are used for (quantitative) chemical depth profiling with nanometer depth resolution and part per million level detection limits. We have both GD-OES and GD-TOFMS instruments.
- a Raman microscope, capable of also using the surface-enhanced and tip-enhanced Raman effects (SERS and TERS respectively). This can be used for stress mapping on a sub-micron spatial scale.
- a high spatial resolution Secondary Ion Mass Spectrometer (SIMS), integrated within a dual beam SEM-FIB instrument. This is used for chemical imaging (including depth profiles) on a smaller spatial scale than can be accessed by the glow discharge instruments.
There is an increasing demand, both from industry and research community, to characterize small-scale and site-specific mechanical properties of materials.
The motivation behind such demand is two folds:
- the need to reliably predict the performance of miniature mechanical systems (MEMS, UV-LIGA watch parts, coated components like machining tools etc.) and microelectromechanical systems (MEMS/NEMS/MOEMS);
- to develop detailed and accurate hierarchical models of the mechanical behavior of complex, multicomponent structural materials.
This requires the development of new micro-scale instruments and testing methods to study the deformation behavior of small mechanical parts and to investigate size effects in mechanical properties.
The topics of our high quality services are closely related to the research activities mentioned above. For applied research for industries, SMEs, associations, federal agencies and private customers we maintain a modern and efficient testing infrastructure and analytic equipment. We characterise in particular mechanical properties of materials, provide state of the art surface and microstructure analysis facilities and offer prototyping facilities for surface patterning via UV-, electron- and ion beam patterning methods.