AUTHOR=Ju Jaehyung , Gao Xin-Lin TITLE=Editorial: Mechanical Metamaterials: Cutting-Edge Metastructures JOURNAL=Frontiers in Mechanical Engineering VOLUME=8 YEAR=2022 URL=https://www.frontiersin.org/journals/mechanical-engineering/articles/10.3389/fmech.2022.868418 DOI=10.3389/fmech.2022.868418 ISSN=2297-3079