Large-scale and high-efficient water collection of microfibers with long-term durability still remains challenging. Here we present well-controlled, bioinspired spindle-knot microfibers with cavity knots (named cavity-microfiber), precisely fabricated via a simple gas-in-water microfluidic method, to address this challenge. The cavity-microfiber is endowed with unique surface roughness, mechanical strength, and long-term durability due to the design of cavity as well as polymer composition, thus enabling an outstanding performance of water collection. The maximum water volume collected on a single knot is almost 495 times than that of the knot on the cavity-microfiber. Moreover, the spider-web-like networks assembled controllably by cavity-microfibers demonstrate excellent large-scale and high-efficient water collection. To maximize the water-collecting capacity, nodes/intersections should be designed on the topology of the network as many as possible. Our light-weighted yet tough, low-cost microfibers with high efficiency in directional water transportation offers promising opportunities for large-scale water collection in water-deficient areas.

Bacterial adhesion and colonization can result in chronic non‐healing wounds. Current hydrophilic wound dressings can release antibacterial agents into the wound exudate, but may result in overhydrated wounds, bacterial overgrowth, and even tissue maceration. Hydrophobic dressings are anti‐fouling, though ineffective to encapsulate and release bactericidal agents. Combining the advantages of hydrophilic and hydrophobic dressings seems difficult, until the development of superwettability surfaces offers an opportunity for omniphobic dressings from intrinsic hydrophilic polymers. Herein, omniphobic porous hydrogel wound dressings loaded with a zinc imidazolate framework 8 (ZIF‐8) are fabricated by a microfluidic‐emulsion‐templating method. The fabricated porous hydrogel membrane with its reentrant architecture is repellent to blood and body fluids, though intrinsically hydrophilic. This unique combination not only reduces the adhesion of harmful microbes, but also enables the encapsulation and release of antibacterial ingredients to wounded sites from hydrophilic polymer networks. As such, the omniphobic metal‐organic frameworks (MOFs)@hydrogel porous wound dressing can inhibit bacteria invasion and enable the controlled release of the bactericidal, anti‐inflammatory, and nontoxic zinc ions. Furthermore, in vivo study of infected full‐thickness skin defect models demonstrates that the dressing also accelerates wound closure by promoting angiogenesis and collagen deposition. Therefore, the omniphobic MOFs@hydrogel porous wound dressings are potentially useful for clinical application.

Non-stick, ultra-elastic liquid metal droplets were fabricated by coating PTFE particles onto the surface of NaOH-treated liquid metal droplets.

Hydrogel bioelectronics that can interface biological tissues and flexible electronics is at the core of the growing field of healthcare monitoring, smart drug systems, and wearable and implantable devices. Here, a simple strategy is demonstrated to prototype all‐hydrogel bioelectronics with embedded arbitrary conductive networks using tough hydrogels and liquid metal. Due to their excellent stretchability, the resultant all‐hydrogel bioelectronics exhibits stable electrochemical properties at large tensile stretch and various modes of deformation. The potential of fabricated all‐hydrogel bioelectronics is demonstrated as wearable strain sensors, cardiac patches, and near‐field communication (NFC) devices for monitoring various physiological conditions wirelessly. The presented simple platform paves the way of implantable hydrogel electronics for Internet‐of‐Things and tissue–machine interfacing applications.

Natural fiber systems provide inspirations for artificial fiber spinning and applications. Through a long process of trial and error, great progress has been made in recent years. The natural fiber itself, especially silks, and the formation mechanism are better understood, and some of the essential factors are implemented in artificial spinning methods, benefiting from advanced manufacturing technologies. In addition, fiber-based materials produced via bioinspired spinning methods find an increasingly wide range of biomedical, optoelectronic, and environmental engineering applications. This paper reviews recent developments in the spinning and application of bioinspired fiber systems, introduces natural fiber and spinning processes and artificial spinning methods, and discusses applications of artificial fiber materials. Views on remaining challenges and the perspective on future trends are also proposed.

Biological systems have evolved over billions of years to develop wetting strategies for advantageous structure-property-performance relations that are crucial for their survival. The discovery of these intriguing relationships has inspired tremendous efforts to investigate the micro/nanoscale features of naturally occurring structures with superwettability. Researchers have since developed new methods and techniques to construct artificial materials that mimic natural structures and functionalities. Here, a brief review of natural hierarchical architectures with liquid repellent properties is presented, and the critical underlying mechanism is summarized with an emphasis on the micro/nanoscopic architectures. The state-of-the-art micro/nanofabrication techniques for creating bioinspired hierarchical superwettability structures that are categorized by random and exquisite features are also reviewed, followed by an overview of their emerging applications, with special attention to biomedical-related fields. The development of fabrication techniques enhances capabilities relative to those of living systems, paving the way toward advanced structural materials with superior functions and unprecedented characteristics for potential applications. Figure 1. Natural superwettable surfaces. Scanning electronic microscopy (SEM) images demonstrate the surface micro/nanostructures of a) lotus leaf, [4] b) Salvinia molesta, [115] c) cicada wings, [109] d) mosquito eye, [37] e) cactus spines, [110] f) desert beetle, [2] g) water strider, [5] h) springtail skin, [145] and i) pitcher plant. [50] The examples represent a range of different intelligent surfaces that exist in nature. Reproduced with permission. [4]

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Vitamin MOF-laden microfibers with alginate shells and copper- or zinc-vitamin framework cores are controllably generated for improving tissue wound healing.