Research lead
Scientists at Risø DTU have shown that materials used in the production of micro- and nano- components react very differently depending on the size of the crystals they contain.
The findings are important for the development of technology for the nanoproduction of micro-electro-mechanical systems such as digital microphones in mobile phones, miniature pressure sensors in water pumps and acceleration sensors in airbags.
Materials at nanoscale often react differently from their larger-scale counterparts, making it necessary to build new understanding of what happens when they are squeezed, flattened or stamped out, when manufacturing nanocomponents.
The researchers used transmission electron microscopy (TEM) to study what happens when nanosize crystals of titanium are deformed, showing titanium crystals of a certain size are deformed in such a way that each atom is systematically displaced in proportion to the neighbouring atoms, resulting in a macroscopic deformation. This process is called deformation twinning.
When the titanium crystals become smaller, they are much more difficult to deform. However, at 1 micrometre and below the behaviour of the titanium crystals changes again, and they are deformed in the same way as very large crystals. This kind of deformation is called dislocation plasticity. The researchers say the discovery has significance in showing how to produce nanocomponents of metal and ceramics to ensure the final component has the desired properties.