Full-field measurements for the mechanics of micrometer-sized structures

As micromachined commercial products with mechanical features today exploit only the integration capabilities microfabrication technologies allow (for mass-production of reliable products), there is room for innovative products making the most of micrometer-sized objects, which are very specific from the mechanical point of view for two reasons:- Their surface/volume ratio is much larger than for the objects mechanical engineers are used to deal with. The consequence is that strong surface couplings have been evidenced, translating changes in the (electro-) chemical environment into mechanical deformation.- the geometric margins (compared to the dimensions) and the material homogeneity resulting from the usual processing techniques are very poor.As a consequence, studying the mechanical behavior of micrometer-sized objects requires to overcome two main barriers:- To identify material constitutive laws at the micrometer scale and to quantify the role of the environment on the behavior;- To model chemo-mechanical couplings when materials are heterogeneous and structures are poorly defined.Moving forward along these two lines requires the development of a dedicated instrumentation and the use of identification techniques suited both to the available experimental data and to the proposed mechanical descriptions. As a consequence: - The full-field measurements techniques proposed within the last few years for the mechanical characterization at the micrometer scale are presented, and the various extensions of scanning microdeformation microscopy toward a quantitative local characterization of anisotropic thin-film materials are detailed.- The various experimental tools developed to measure and control chemo-mechanical surface couplings are first described, and two proposed frameworks for modeling these surface couplings (based on asymptotic analysis and on second-strain gradient elasticity) are detailed