This book presents selected, peer-reviewed proceedings of the International Conference on Advanced Mechanical Engineering, Automation and Sustainable Development 2021 (AMAS2021), held in the city of Ha Long, Vietnam, from November 4 to 7, 2021. AMAS2021 is a special meeting of the International Conference on Material, Machines and Methods for Sustainable Development (MMMS), with a strong focus on automation and fostering an overall approach to assist policy makers, industries, and researchers at various levels to position local technological development toward sustainable development. The contributions published in this book stem from a wide spectrum of research, ranging from micro- and nanomaterial design and processing, to special applications in mechanical technology, environmental protection, green development, and climate change mitigation. A large group of contributions selected for these proceedings also focus on modeling and manufacturing of ecomaterials.