Extreme Mechanics of Metamaterials: From ideal to realistic conditions

Descripción del proyecto

Materiales eficientes para uso aeroespacial y protésico

Los metamateriales mecánicos son estructuras artificiales que pueden ser ligeras y resistentes al mismo tiempo. También pueden cambiar de forma autónoma para lograr la funcionalidad deseada. La técnica de fabricación digital ha evolucionado tanto en los últimos años que estos materiales han empezado a emplearse en el ámbito de la mecánica y ha aumentado su número de funcionalidades. En el proyecto Extr3Me, financiado con fondos europeos, se examinará el efecto de las condiciones de frontera no homogéneas. Además, se estudiará la sensibilidad a las imperfecciones geométricas y se considerará el papel de la disipación. El objetivo principal del proyecto es investigar los límites de la mecánica de sólidos y diseñar funcionalidades sólidas avanzadas que se adapten a una amplia variedad de ámbitos.

Objetivo

Manipulating physical signals such as light, sound, heat or motion is a vital challenge in multiple areas of science. Due to recent advances in digital fabrication techniques, the last years have seen a revolution in artificial periodic composites with on-demand electromagnetic, acoustic, thermal and mechanical properties. These so-called metamaterials become particularly interesting in mechanics, where geometrical effects and nonlinearities are much stronger than in any other physical field. Over the past 5 years, the community -including myself- has discovered a plethora of “extreme” functionalities, e.g. mechanical metamaterials that are very light, stiff and strong at the same time, that have negative elastic moduli or that exhibit programmable shape-changes. Importantly, such advanced properties are typically designed through a purely geometrical framework. Yet, this impressive progress is so far confined to idealized settings, namely for homogeneous boundary conditions, imperfection-free structures and purely elastic constituents under quasi-static driving. This traditional focus severely limits our understanding of metamaterials and their potential for applications. Here, I propose to uncover the extreme mechanics of metamaterials under realistic conditions. Specifically, by generalizing the geometrical framework to allow for deviations from the ideal limit, and by validating it through a wide array of experimental and numerical techniques, I will establish: 1) the effect of inhomogeneous boundary conditions; 2) the sensitivity to geometric imperfections; 3) the role of dissipation. Just as the fundamental understanding of defects and dislocations revolutionized materials science, by exploring perturbations in metamaterials I will push the frontiers of solids mechanics and open up avenues for the design of robust advanced functionalities tailored to realistic complex scenarios, from prosthetics to aerospace.