Mechanically Robust,Elastic, and Healable Ionogels for Highly Sensitive Ultra-Durable Ionic Skins

The fabrication of highly durable skin-mimicking sensors remains challenging because of the unavoidable fatigue and physical damage that sensors are subjected to in practical applications. In this study, ultra-durable ionic skins (I-skins) with excellent healability and high sensitivity are fabricated by impregnating ionic liquids (ILs) into a mechanically robust poly(urea-urethane) (PU) network. The PU network is composed of crystallized poly(ε-caprolactone) and flexible poly(ethylene glycol) that are dynamically cross-linked with hindered urea bonds and hydrogen bonds. Such a design endows the resultant ionogels with high mechanical strength, good elasticity, Young's modulus similar to that of natural skin, and excellent healability. The ionogel-based I-skins exhibit a high sensitivity to a wide range of strains (0.1–300%) and pressures (0.1–20 kPa). Importantly, the I-skins show a highly reproducible electrical response over 10 000 uninterrupted strain cycles. The sensing performance of the I-skins stored in open air for 200 days is almost the same as that of the freshly prepared I-skin. The fractured I-skins can be easily healed by heating at 65 °C that restores their original ultra-durable sensing performance. The long-term durability of the I-skins is attributed to the combination of non-volatility of the ILs, excellent healability, and well-designed mechanical properties.     

Bacterially Produced,Nacre‐Inspired Composite Materials

The impressive mechanical properties of natural composites, such as nacre, arise from their multiscale hierarchical structures, which span from nano‐ to macroscale and lead to effective energy dissipation. While some synthetic bioinspired materials have achieved the toughness of natural nacre, current production methods are complex and typically involve toxic chemicals, extreme temperatures, and/or high pressures. Here, the exclusive use of bacteria to produce nacre‐inspired layered calcium carbonate‐polyglutamate composite materials that reach and exceed the toughness of natural nacre, while additionally exhibiting high extensibility and maintaining high stiffness, is introduced. The extensive diversity of bacterial metabolic abilities and the possibility of genetic engineering allows for the creation of a library of bacterially produced, cost‐effective, and eco‐friendly composite materials.     

Bio‐Inspired,Smart, Multiscale Interfacial Materials

In this review a strategy for the design of bioinspired, smart, multiscale interfacial (BSMI) materials is presented and put into context with recent progress in the field of BSMI materials spanning natural to artificial to reversibly stimuli‐sensitive interfaces. BSMI materials that respond to single/dual/multiple external stimuli, e.g., light, pH, electrical fields, and so on, can switch reversibly between two entirely opposite properties. This article utilizes hydrophobicity and hydrophilicity as an example to demonstrate the feasibility of the design strategy, which may also be extended to other properties, for example, conductor/insulator, p‐type/n‐type semiconductor, or ferromagnetism/anti‐ferromagnetism, for the design of other BSMI materials in the future.     

Designing with Light: Advanced 2D, 3D,and 4D Materials

Recent achievements and future opportunities for the design of 2D, 3D, and 4D materials using photochemical reactions are summarized. Light is an attractive stimulus for material design due to its outstanding spatiotemporal control, and its ability to mediate rapid polymerization under moderate reaction temperatures. These features have been significantly enhanced by major advances in light generation/manipulation with light-emitting diodes and optical fiber technologies which now allows for a broad range of cost-effective fabrication protocols. This combination is driving the preparation of sophisticated 2D, 3D, and 4D materials at the nano-, micro-, and macrosize scales. Looking ahead, future challenges and opportunities that will significantly impact the field and help shape the future of light as a versatile and tunable design tool are highlighted.     

材料信息学平台的研究现状发展趋势与作用

调查分析了材料信息学平台研究与应用的现状,指出了材料信息学平台已成为材料研发的最重要的设备之一,展望了新一代材料信息学平台的发展趋势, 概述了材料信息平台对于材料研究与发展的重要促进作用,认为材料信息学平台的应用将加速材料科学与工程的发展,引起材料研究模式的变革.     

TiO2 anatase nanoparticle networks: synthesis, structure, and electrochemical performance

Nanocrystalline anatase TiO(2) materials with different specific surface areas and pore size distributions are prepared via sol-gel and miniemulsion routes in the presence of surfactants. The samples are characterized by X-ray diffraction, nitrogen sorption, transmission electron microscopy, and electrochemical measurements. The materials show a pure anatase phase with average crystallite size of about 10 nm. The nitrogen sorption analysis reveals specific surface areas ranging from 25 to 150 m(2) g(-1) . It is demonstrated that the electrochemical performance of this material strongly depends on morphology. The mesoporous TiO(2) samples exhibit excellent high rate capabilities and good cycling stability.     

A Strong,Tough, and Scalable Structural Material from Fast-Growing Bamboo

Lightweight structural materials with high strength are desirable for advanced applications in transportation, construction, automotive, and aerospace. Bamboo is one of the fastest growing plants with a peak growth rate up to 100 cm per day. Here, a simple and effective top-down approach is designed for processing natural bamboo into a lightweight yet strong bulk structural material with a record high tensile strength of ≈1 GPa and toughness of 9.74 MJ m⁻³. More specifically, bamboo is densified by the partial removal of its lignin and hemicellulose, followed by hot-pressing. Long, aligned cellulose nanofibrils with dramatically increased hydrogen bonds and largely reduced structural defects in the densified bamboo structure contribute to its high mechanical tensile strength, flexural strength, and toughness. The low density of lignocellulose in the densified bamboo leads to a specific strength of 777 MPa cm³ g⁻¹, which is significantly greater than other reported bamboo materials and most structural materials (e.g., natural polymers, plastics, steels, and alloys). This work demonstrates a potential large-scale production of lightweight, strong bulk structural materials from abundant, fast-growing, and sustainable bamboo.     

Functional gradients and heterogeneities in biological materials: Design principles,functions, and bioinspired applications

Living organisms have ingeniously evolved functional gradients and heterogeneities to create high-performance biological materials from a fairly limited choice of elements and compounds during long-term evolution and selection. The translation of such design motifs into synthetic materials offers a spectrum of feasible pathways towards unprecedented properties and functionalities that are favorable for practical uses in a variety of engineering and medical fields. Here, we review the basic design forms and principles of naturally-occurring gradients in biological materials and discuss the functions and benefits that they confer to organisms. These gradients are fundamentally associated with the variations in local chemical compositions/constituents and structural characteristics involved in the arrangement, distribution, dimensions and orientations of the building units. The associated interfaces in biological materials invariably demonstrate localized gradients and a variety of gradients are generally integrated over multiple length-scales within the same material. The bioinspired design and applications of synthetic functionally graded materials that mimic their natural paradigms are revisited and the emerging processing techniques needed to replicate the biological gradients are described. It is expected that in the future bioinspired gradients and heterogeneities will play an increasingly important role in the development of high-performance materials for more challenging applications.