The advancement of acoustic metamaterials has opened up a novel perspective for addressing the challenge of low-frequency broadband noise control. Drawing inspiration from the design principles of acoustic metamaterials, our team has introduced efficient  absorption mechanisms for low-frequency sound, achieving flexible and efficient noise control. We have developed efficient manufacturing processes for metamaterials, compiled systematic research findings and solutions, and facilitated the large-scale engineering applications of metamaterials. This report highlights the recent progress in metamaterial design, device development, and equipment applications, mainly including low-frequency broadband design methods for sound-absorbing metamaterials, sound absorption performance optimization methods, and related typical applications such as laboratories, anechoic chambers, and sound barriers.

Dr. Chongrui Liu received his BE degree in Mechanical Engineering from the Shandong University in 2010, MD degree and PHD degree in Mechanical Engineering from Xi'an Jiaotong University in 2013 and 2020. He served as  assistant professor in School of Mechanical Engineering at Xi’an Jiaotong University from 2020 to 2024, and is currently associate professor in School of Mechanical Engineering at Xi’an Jiaotong University. His main research focuses on the application and industrialization of acoustic metamaterials, along with vibration and noise control in high-end equipment. He has published over 30 high-quality academic papers, two of which have received the IOP Highly Cited Paper Award. Additionally, he has applied for 10 invention patents and authored a monograph titled "Theory and Application of Acoustic Metamaterial Sound Absorption". His research findings have been positively evaluated and widely cited by experts in the field, amassing a total of 1,095 citations on Web of Science (with 1,004 citations from other sources). He has spearheaded multiple projects concerning sound-absorbing and insulating metamaterials, including those funded by the National Natural Science Foundation of China, the China Postdoctoral Science Foundation, the Aviation Science Foundation, the Innovation Fund of the First Academy of China Aerospace Science and Technology Corporation, as well as various projects from the Science and Technology Industry Bureau and the Equipment Development Department. Currently, he has successfully achieved comprehensive industrial application of sound-absorbing and insulating metamaterials.