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Inspired by natural porous architectures, numerous attempts have been made to generate porous structures. Owing to the smooth surfaces, highly interconnected porous architectures, and mathematical controllable geometry features, triply periodic minimal surface (TPMS) is emerging as an outstanding solution to constructing porous structures in recent years. However, many advantages of TPMS are not fully utilized in current research. Critical problems of the process from design, manufacturing to applications need further systematic and integrated discussions. In this work, a comprehensive overview of TPMS porous structures is provided. In order to generate the digital models of TPMS, the geometry design algorithms and performance control strategies are introduced according to diverse requirements. Based on that, precise additive manufacturing methods are summarized for fabricating physical TPMS products. Furthermore, actual multidisciplinary applications are presented to clarify the advantages and further potential of TPMS porous structures. Eventually, the existing problems and further research outlooks are discussed.

Acoustic metamaterials (AMs), which are materials composed of subwavelength periodic artificial structures with specific designs, have drawn significant research attention. This is because of the extraordinary abilities of AMs to manipulate acoustic waves compared with those of traditional acoustic materials. In this review, current advances in AM research are comprehensively investigated and summarized. First, major theories regarding AMs, including the acoustic wave equation, crystal lattice and energy band theory, effective medium theory, and general Snell's law, are explained in detail. Existing AM structures are then described and divided into several categories based on their structural characteristics and responses to acoustic waves. Furthermore, to bridge the gap between design and practical application, both conventional and advanced AM manufacturing methods are summarized. The applications of AMs in the fields of acoustic cloaking, acoustic lensing, acoustic absorption, noise reduction, and supernormal sound transmission are particularly delineated. Finally, contemporary challenges, trends, and strategies relevant to AMs are discussed. This review aims to provide a comprehensive collection of AM‐related knowledge, including information regarding physical theories, structures, fabrication approaches, and applications, which will help promote the further development of AMs.

Auxetic mechanical metamaterials (AMMs), as an exciting paradigm of metamaterials, have attracted increasing attention due to their interesting mechanical properties (e.g. negative Poisson's ratio), as well as the emergence of advanced manufacturing technology (e.g. 3D printing). Although various reviews on AMMs, their structures, properties, and applications, have existed, it still lacks a comprehensive review in terms of manufacturing methods. Herein, the latest progress in AMMs is extensively reviewed, including AMMs' structures, characteristics, manufacturing methods, and applications. In addition, the current challenges and future works of AMMs are concluded and discussed. This Review aims to serve as a collection of knowledge that supplies more comprehensive understanding and inspiration to support further developments of AMMs from the perspective of design and manufacturing.

Liquid-metal (LM)-based flexible and stretchable electronics have attracted widespread interest in wearable health monitoring, electronic skins, and soft robotics. However, it is challenging to directly pattern LMs on soft substrates...