Micro-lattices for wide-band three-dimensional elastic wave attenuation

The past decade has witnessed the emergence of three-dimensional micro-lattices and state-of-the art manufacturing techniques that have enabled their realization. The ability to fabricate bulk materials that are precisely architected at the microscopic scale is exhilarating to various scientific communities. This has thus greatly revived the yearning for futuristic multifunctional materials. From the perspective of mechanical wave propagation, this implies complete control over micro-structure that can be designed for exotic wave-based applications. In this work, we put forth new design strategies to engineer micro-lattices for desirable elastic wave bandgaps and discuss their experimental realization. The band gaps can be attributed to local resonance and Bragg mechanisms and can be precisely tuned via both unit cell geometry and the intrinsic material employed for its fabrication. Alongside being thin, lightweight and/or displaying a negative Poisson’s ratio, our micro-lattices are equipped with the capability of attenuating elastic waves in all directions over a wide frequency range and can facilitate novel elastic wave functional materials.