LAUSR

Architected materials have facilitated a significant breakthrough in the control of the mechanical behavior of structures. Most notably, metamaterials with unprecedented properties can be easily designed in large scales, exhibiting high strength, tunability of their properties, resilience or versatility to large deformations, and auxetic behavior. In addition, 4D printed structures can modify their shape depending on the working environment. Due to their chemical composition, these structures can modify their mechanical and electrochemical properties based on external stimuli. This mechanism has substantial implications on the mechanical response of the material, furnishing stiffening of the structure or malleability on demand. Furthermore, designing structures that are also adaptive to actuation has given rise to the design of flexible 3D-printed mechanisms. Flexible structures can be utilized for engineering applications requiring large but recoverable deformations, continuous motion, and high precision. A characteristic category of structures encompassing these properties are soft robotics. Soft robotic mechanisms are composed of rubber materials that can be electrically actuated to sustain nonlinear deformations. Combining these designs with much stronger fiber components leads to the design of artificial muscles, imitating animal motion and having a significantly higher strength than simple soft robot systems. Nevertheless, metamaterials also exhibit remarkable properties that are not observed in conventional systems. A characteristic example is the transport of mechanical signals with the proclivity to a specific direction. This has been accomplished through the design of nonreciprocal mechanical metamaterials. In regular materials, the transmission of any physical quantity, such as mechanical signals or mechanical waves, is identical, regardless of geometrical or material asymmetries and defects between any two points in space. However, nonreciprocal metamaterials can alter this behavior, giving directionality to the transport of these mechanical quantities. This is the paragon of the next-generation mechanical signal transport, isolation, and energy storage. In addition, the combination of the architected design with the macroscopic dynamic loading conditions can provide the formation of distinct elastic vector solitons. These coupled waves can have significantly different formations depending on the direction of the wave, controlling not only the direction of the signal, but also its shape. The inexorable advances in 3D printing technology have enabled the fabrication of these structures. Techniques such as fused deposition modeling (FDM), Z. Vangelatos, Z. Zhang, Prof. G. X. Gu, Prof. C. P. Grigoropoulos Department of Mechanical Engineering University of California, Berkeley Berkeley, CA 94720, USA E-mail: [email protected]; [email protected]; [email protected]; [email protected] Z. Vangelatos, Prof. C. P. Grigoropoulos Department of Mechanical Engineering Laser Thermal Laboratory University of California, Berkeley Berkeley, CA 94720, USA Z. Zhang, Prof. G. X. Gu Gu Research Group Department of Mechanical Engineering University of California, Berkeley Berkeley, CA 94720, USA