Inspired by electromagnetic metamaterials, mechanical metamaterials have been a focus in various fields. In recent years, benefited from the rapid development of 3D printing and automated machine learning designing methods, the mechanical metamaterials study has achieved a series of excellent results, enabling metamaterials to have unconventional and counterintuitive mechanical properties that are rare or even non-existent in nature. Unlike common materials, the properties of mechanical metamaterials are mainly derived from artificial structures rather than chemical components, which permits a huge designing space. This article reviews some relevant research highlights of mechanical metamaterials of 2021 in terms of unusual mechanical properties, intelligent design methods and additive manufacturing-based fabrication technology, in which the fusion of mechanical metamaterials and machine learning, modular design and 3D printing is focused and discussed.

mechanical metamaterials  /  machine learning  /  3D printing