Advances in Biomimetic Materials

Biomimetic materials refer to a category of materials that draw inspiration from the natural world, and mimic the remarkable properties and functionalities found in biological systems. In an effort to showcase advancements in biomimetic materials, we curated a Special Issue titled "Advances in Biomimetic Materials". This collection features contributions from prominent scientists in the field, comprising 8 reviews and 8 research articles. It offers valuable insights into the latest developments across a wide range of topics, including fabrication strategy, materials, and diverse applications of biomimetic materials in various fields. A significant number of existing synthesis processes and materials exhibit adverse environmental impacts and offer limited control over the size, shape, and phase of the resulting materials. In response to these environmental concerns, Helmut Cölfen et al. (smtd.202300575) report a novel type of mineral plastics by physically cross-linking (poly)glutamic-acid (PGlu) using different alcohol-water mixtures, metal ion ratios, and molecular weights. The resulting PGlu/CaFe mineral plastics are bio-based and biodegradable. They contain nitrogen, calcium, and iron to support the growth of microorganisms and expedite the biodegradation process. Taking inspiration from the natural high-magnesium calcite (HMC) in biological materials, Shu-Hong Yu et al. (smtd.202300236) devise a practical approach to fabricate fluffy dumbbell-shaped HMC with a large specific surface area, which greatly enhances their ability to reduce the chemical oxygen demand in lake water contaminated by organic substances. Further, David Kisailus et al. (smtd.202301227) present a comprehensive review on the advancements and possibilities of bio-inspired approaches for creating functional materials that cater to environmental applications. The authors also discuss the obstacles and potential opportunities associated with the development of sustainable and efficient processes and technologies in this domain. Nature is abundant with extraordinary hierarchical materials that offer valuable inspiration to the development of artificial substances. Biological macroporous materials, such as plant stems and animal bones, exhibit remarkable properties through the precisely organized architecture created from a limited number of components. Hao Bai et al. (smtd.202300213) review the assembly of MXene through ice-templating techniques for macroporous materials. The freezing processes and potential mechanisms are analyzed, and the diverse applications of bioinspired MXene-based materials are exemplified. Inspired by biological ion channels, a wide range of artificial subnano channels with enhanced ion selectivity and permeability have been recently developed showing great potential in efficient separation, energy conversion, and biosensing. Huacheng Zhang et al. (smtd.202300278) summarize various methods for fabricating subnanofluidics pores, channels, tubes, and slits, and the functionalization techniques of subnanochannels through the incorporation of functional groups. Takashi Kato et al. (smtd.202300353) successfully synthesize ordered and nanoporous structures of zinc oxide materials in two and one dimensions by the conversion of liquid-crystalline zinc hydroxide carbonate (ZHC) nanoplates, which are obtained by a biomineralization-inspired method. Shutao Wang et al. (smtd.202300531) present the synthesis of nanofractal magnetic particles (nanoFMPs) using a mediator monomer-regulated emulsion interfacial polymerization to mimic the morphologies of immune cells. These nanoFMPs exhibit efficient performance in nucleic acid separation. Wenlong Song et al. (smtd.202300753) provide an overview of the underlying principles behind the formation of bioinspired supramolecular hydrogels through non-covalent interactions, further discuss the dynamic assembly or disassembly of these hydrogels under stimuli, and exemplify their applications in relation to natural objects including humans, animals, and plants. Huai-Ping Cong et al. (smtd.202300414) review the utilization of nanocomposite hydrogels as soft actuators with elaborate and programmable structures achieved through the assembly of nano-objects in the hydrogel matrix. The nanocomposite hydrogels exhibit exceptional capabilities, including bending, spiraling, patterned deformations, and biomimetic complex shape changes, thereby demonstrating significant promise in fields such as mobile robots, energy harvesting, and biomedical applications. Bio-inspired superwetting materials and their applications have attracted widespread attention in recent years. In order to achieve both static liquid repellency and pressure resistance, taking inspiration from the Springtail, Zuankai Wang et al. (smtd.202201602) engineer an innovative surface known as armored reentrants (AR). This surface consists of two distinct hierarchical structures: a micrometric reentrant structure for static liquid repellency, and a nanometric reentrant structure for pressure resistance. By incorporating these structures, the AR surface is capable of repelling liquids with low surface tensions while effectively withstanding high pressure exerted by the liquids. Huan Liu et al. (smtd.202300270) summarize bioinspired fibrous materials with superhydrophobic properties focusing on different dimensions of the fibers, and discuss natural systems and mechanisms of superhydrophobic fibrous materials, as well as artificial fibers and their various applications, which will inspire the design and manufacturing of superhydrophobic fibrous systems. Jianjun Wang et al. (smtd.202300407) conduct a quantitative analysis to investigate the influence of surface morphology and molecular composition of potassium-feldspar on ice nucleation, confirming the importance of the molecular component and structure specificity in facilitating ice nucleation. Inspired by the peristome surface of Nepenthes pitcher, Pengchao Zhang et al. (smtd.202300221) report the directional superspreading of water droplets on hydrogel surfaces with shaped microchannels, such as periodic, bended, shunted, divergent, and confluent morphologies, showing great potentials for the development of open microfluidic platforms for various healthcare-related applications. Xi Yao et al. (smtd.202300253) provide an overview of the principles and novel methods for droplet manipulation on bioinspired liquid-infused surfaces (LIS), highlight their applications in anti-biofouling and pathogen control, biosensing, and the development of digital microfluidics, and discuss the key challenges and opportunities with droplet manipulation on LIS. Jian Jin et al. (smtd.202300247) report a zero-oil-fouling membrane by grafting a considerably high coverage of zwitterionic polymer and constructing a flawless hydration defense barrier on the surface. This membrane demonstrates remarkable resistance to oil fouling when used to separate multitudinous oil-in-water emulsions with an impressively low decline in flux (0%), ∼100% flux recovery, and a notably high water flux of ∼800 L m−2 h−1 bar−1. Kai Xiao et al. (smtd.202300261) provide a comprehensive overview on the mechanisms and potential applications of interfacial-based energy generators with various types of interfaces, including solid-solid, solid-liquid, liquid-liquid, and gas-contained interfaces, which offers a promising pathway for the development of inexhaustible and environmental-friendly power generation to solve energy crisis. This special issue in Small Methods offers a global forum for disseminating the notable advancements in biomimetic materials and their prospective applications. Additionally, it is our aspiration that this special issue stimulates increased engagement and cooperation among researchers and practitioners from various fields. We extend our sincere gratitude to all the authors for their exceptional contributions, which truly exemplify the cutting-edge advancements in this particular field. We also extend our heartfelt appreciation to the editorial team of Small Methods, particularly Dr. Emily Hu for granting us the opportunity to publish this special issue. The authors declare no conflict of interest. Shutao Wang is a full professor at Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. He obtained his PhD degree in 2007 at Institute of Chemistry, Chinese Academy of Sciences (ICCAS). He then worked as a postdoctoral researcher in the Department of Molecular and Medical Pharmacology and California NanoSystem Institute at the University of California in Los Angeles (2007–2010). Subsequently, he was appointed as a full Professor of Chemistry from 2010–2014 at ICCAS. His scientific interests focus on the design and synthesis of bio-inspired interfacial materials with special adhesion and their applications at the nano-biointerface. Shu-Hong Yu completed PhD in inorganic chemistry in 1998 from University of Science and Technology of China. From 1999 to 2001, he worked in Tokyo Institute of Technology as a Postdoctoral Fellow, and was awarded the AvH Fellowship (2001-2002) in the Max Planck Institute of Colloids and Interfaces, Germany. He was appointed as a full professor in 2002 and the Cheung Kong Professorship in 2006. He was elected as Academician of Chinese Academy of Sciences in 2019. His research interests include bio-inspired synthesis of inorganic nanostructures, self-assembly of nanoscale building blocks, nanocomposites, their related properties and applications.