Multistable metamaterials are engineered structures capable of reconfiguring between distinct equilibrium states, offering extraordinary functionality, such as substantial energy dissipation and nonlinear wave propagation. However, current implementations rely predominantly on macroscale, polymer-based fabrication, resulting in architectures suffering from geometric defects, wave attenuation, and limited scalability. Transitioning to silicon-based microfabrication provides a scalable route to realize low-loss, nearly defect-free reconfigurable metamaterials, overcoming these limitations. Yet, this approach entails new challenges in operation, wave generation, and testing at the microscale.
To address these challenges, this talk will present a framework for multistable reconfigurable metamaterials on a chip, encompassing their realization, actuation, and characterization across quasistatic and dynamic regimes. First, I will present the microfabrication of bistable micro-elements and their assembly into wafer-level, silicon-based chains with unprecedented numbers of unit cells. Next, I will introduce a novel in-situ method for measuring the non-monotonic force-displacement relation characteristic of bistable elements – directly at the microscale. Finally, I will address the critical bottleneck of triggering nonlinear transition waves in micro-architectures, enabling their first experimental investigation at small scales and in a silicon medium. This breakthrough unlocks tailored wave control through design, and particularly, complex, non-constant wavefront velocity profiles achieved by engineering aperiodic, functionally graded architectures.
Ultimately, this framework provides a controlled testbed for experimental nonlinear dynamics, enables on-chip mechanical signal manipulation, and paves the way for the integration of metamaterials with microelectromechanical systems (MEMS). I will conclude by sharing my vision and future opportunities for hierarchically smart architected matter across length scales.
