Microsprings and microcantilevers: studies of mechanical response

Porous thin films with unique microstructures have been fabricated with the glancing angle deposition technique. This technique utilizes highly oblique deposition angles to make use of initial growth and shadowing conditions, which allow thin films consisting of microsprings and arrays of microcantilevers to be engineered with nanometre scale control. The mechanical properties of these microstructured films were studied with a nanoindentation technique. Several microscopic 'springbed' films were tested over a range of forces using a spherical indenter tip. The geometries of the microsprings were varied, and a number of different materials were used to fabricate these films, which were typically a few micrometres thick. Slanted post arrays, resembling microscopic cantilevers, were also subjected to nanoindentation tests. The results of initial experiments and theory show that these microstructures behave in a manner analogous to macroscopic springs and cantilevers, and may offer opportunities for application as resonator devices.