Freeform microcasting

The global trend towards miniaturization has led to the development of innumerable miniaturized devices that are now present in our everyday lives. Indeed, the concept of micro-manufacturing has encouraged scientists and engineers to develop new techniques, since a straightforward downscaling of systems and technologies is often not possible. To date, however, there is no existing method capable of solving the issues related to the fabrication of three-dimensional (3D) components of highly complex shape with sub-micron resolution. Powder-based printing processes are typically limited to the size of the powder and lithography-based methods are intrinsically two-dimensional (2D) processes.

The present project, carried out in collaboration with the laboratory of Prof. Yves Bellouard (GALATEA), combines 3D femtosecond laser processing and metal pressure infiltration to provide a new and unique pathway towards the manufacturing at sub-micron resolution of 3D metallic micro‑scale objects and devices that can be embedded in a transparent ceramic substrate having complex features and/or can be freed from the substrate to obtain small free-standing metallic parts of complex shape. The process represents not only a substantial improvement over existing processes but also a new modality for fabricating microdevices. One of the aims of this project is then to unravel the full innovation potential of the process, characterizing and optimize both it and its products. Consequently, to understand and improve the properties of microcast metal structures, conventional mechanical testing of structures produced by this process are being carried out. To this end, free-standing structures of the metal, silver notably, that are amenable for mechanical testing will be produced by removing the substrate. Those will then be tested in uniaxial tension using a rig that has already been designed and built for this purpose.