Low Complexity Testing Micromachines Revealing Size-Dependent Mechanical Properties of Thin Al Films

The mechanical properties measurement of materials with submicron dimensions is extremely challenging, from the preparation and manipulation of specimens, to the application of small loads and extraction of accurate stresses and strains. Here, we describe a novel, versatile concept of micro and nano- machines to test films or beams with characteristic dimensions ranging between 10 nm to 1 mum, allowing multiple loading configurations and geometries. This testing method has been applied to thin, pure aluminium films. The yield strength linearly increases with the inverse of the film thickness, reaching 625 MPa for 150 nm thickness which is 10 times larger than for macroscopic samples.