Materials Science and Engineering: R: Reports最新文献

The reversible phase transition in vanadium dioxide (VO₂) with light, heat, electric, magnetic, and mechanical stimuli is the enabling concept to function as a smart material. It is the basis for the development of numerous varieties of VO₂-based optical, electrochemical, electrical, mechanical, and energy storage devices in micron- to nano-meter scale dimensions on rigid and flexible platforms. Due to its near room temperature (RT) phase transition, VO₂ is considered an excellent alternative and promising candidate to replace the conventional materials used in various applications. Ample interests have been growing to apply VO₂ in novel devices, exploring the device functionality by structural manipulation of VO₂ that could lead to impressive innovations. Much effort is invested in resolving the practical challenges to deal with real-life applications, along with finding out industrially feasible large-scale VO₂-based device fabrication methodology which may act as a stepping stone to embark on the commercial market. In this context, it is crucial to review the recent advancements in devices that use VO₂ smart material as a building element in the device architecture along with the device operation controlled by the phase transition mechanism in VO₂. This review summarizes the new applications of VO₂ in various devices. We start with a brief introduction of the present landscape of various phase transition mechanisms involved in VO₂ followed by significant advantages of VO₂ as a functional material for various applications. In the main part of the paper, the recent five years’ progress in VO₂-based single-stimulus, multi-stimuli, and multifunctional devices, their operation mechanism, and important experimental and theoretical breakthroughs are summarized under each device. Although VO₂ plays a significant role in controlling the device operation, various practical challenges are there to be rectified to further enhance the device performance that would accelerate VO₂-based devices in reaching the commercial platform. Future trends, possible challenges in VO₂-based devices, and potential solutions are presented with perspectives in the final part of the paper.

The application of wearable sensors in domains related to healthcare systems, human motion detection, robotics, and human–machine interactions has attracted significant attention. Because these applications require stretchable, flexible, and non-invasive materials, polymer composites are now at the forefront of research aimed at preparing innovative wearable sensors. Three-dimensional (3D) printing techniques can be used to obtain highly customised and scalable polymer composites to fabricate wearable sensors, which is a challenging task for conventional fabrication techniques. This review provides insights into the prospects of commonly used conductive nanomaterials and 3D printing techniques to prepare wearable devices. Subsequently, the research progress, sensing mechanisms, and performance of 3D-printed wearable sensors, such as strain, pressure, temperature, and humidity sensors, are discussed. In addition, novel 3D-printed multifunctional sensors, such as multi-directional, multi-modal, self-healable, self-powered, in situ printed, and ultrasonic sensors, are highlighted. The challenges and future trends for further research development are clarified.

In the past few decades, electrochemical energy storage systems, represented by alkali metal ion batteries and supercapacitors, have developed rapidly against the background of sustainable development. However, supercapacitors and alkali metal ion batteries, known for the high power density and high energy density, respectively, have struggled to meet the demand of high both power and energy densities energy storage devices. Therefore, integrating both energy storage mechanisms of supercapacitors and alkali metal ion batteries in the same system to attain device with comparatively high both power and energy densities has become the preferred approach for most researchers, and the representatives are assembling hybrid ion capacitors or introducing capacitive contribution into alkali metal ion batteries materials for fast-charging alkali metal ion batteries. For the former, many good quality publications have summarized and evaluated it, while the latter has not. In this review, we systematically summarize and insightfully discuss the phenomenon of introducing capacitive contribution into electrode materials of alkali metal ion batteries. Different methods of identifying capacitive and diffusive behaviors are reviewed, and the origin of the capacitive contribution in the battery materials combining the charge storage mechanism are explained, the influences of electrode materials’ capacitive contribution on battery’s energy and power densities are discussed in detail. Finally, we propose a design idea of electrode materials for battery with high both power and energy densities based on accurately understanding the rational capacitive contribution.

By imitating natural water circulation, artificial water generation processes can produce clean water by utilizing readily available and inexhaustible solar energy. Such a process can address the current global crises related to both energy and water shortages, and expand currently available water resources from rivers, ground water and ice to seawater, brackish water and atmospheric humidity. Among the many materials used for water generation, aerogels offer a great potential due to the inherent combination of three-dimensional, monolithic structure and porous, interconnected network. In this article, we review aerogel-based water generation from brine and atmospheric water. The unique features of aerogels are elucidated from the viewpoint of photo-thermal conversion and water transport. These two components are necessary to achieve efficient solar-driven water production systems. In addition to describing the material specifications, this paper reviews a diversity of structural designs that aim to improve the evaporation performance, including the assembly strategy of light absorption and thermal insulation layers, the reduction of evaporation enthalpy, and the salt-rejection control, as well as Marangoni effect. After evaluating different types of solar-powered water utilization technologies, the paper ends with the challenges for the commercialization and widespread use of aerogel-based water production systems: their disconnect from the current aerogel industry, high production cost and weak mechanical properties, and a lack of standardized performance testing, as well as our future perspective for their application opportunities.

With the increasing attention to energy and environmental issues, the high-efficiency utilization of biomass becomes an exciting new field in the science and technology. Biomass-based functional carbon materials (BFCs) with renewability, flexible structural tunability and diverse physicochemical properties have shown encouraging and bright prospects in the fields of energy conversion and storage. In this review, the recent advances of BFCs in energy conversion and storage are summarized and highlighted, which will shed new lights on the emerging applications of BFCs in wide fields. We comprehensively summarize the synthesis methods of BFCs, which include the strategies of carbonization, activation and functionalization. From the perspectives of multi-dimensional carbon material engineering, the structures and properties of BFCs are presented and analyzed. The recent advances in energy-oriented emerging applications, including photo-catalysis, electro-catalysis, solar cells, supercapacitors, metal ion batteries and microbial fuel cells are systematically summarized and highlighted. Then, this review gives a focus on the significance of establishing the relationship between the structure and performance of BFCs. Finally, the remaining major challenges and opportunities for BFCs in the future are discussed and outlined.

Thermal management has become increasingly critical in a broad range of applications, including cooling electronic devices, regulating body temperature, harvesting solar energy, and so on. To achieve effective thermal management, thermal materials are essential platform that enables various thermal functions such as conduction, insulation, radiation, and absorption. However, it remains challenging to tune these properties in thermal materials by traditional mixing strategy. Alignment engineering has emerged as a promising approach for designing and fabricating thermal structures with extraordinary performance, but hasn’t been systematically summarized yet. In this review we summarize the recent progress in the emerging field of alignment-engineered thermal materials. The state-of-the-art alignment strategies are introduced, and various thermal materials, including alignment-engineered conductive, insulative, emissive, and absorptive materials, are discussed with emphasis on the correlations between alignment approaches and thermal functionalities, and the dynamic balance between ideal structure and practical engineering. Finally, we outline some perspectives on the challenges and opportunities for alignment engineering toward advanced thermal materials and practical applications.

Mechanical metamaterials are engineered materials with unconventional mechanical behavior that originates from artificially programmed microstructures along with intrinsic material properties. With tremendous advancement in computational and manufacturing capabilities to realize complex microstructures over the last decade, the field of mechanical metamaterials has been attracting wide attention due to immense possibilities of achieving unprecedented multi-physical properties which are not attainable in naturally-occurring materials. One of the rapidly emerging trends in this field is to couple the mechanics of material behavior and the unit cell architecture with different other multi-physical aspects such as electrical or magnetic fields, and stimuli like temperature, light or chemical reactions to expand the scope of actively programming on-demand mechanical responses. In this article, we aim to abridge outcomes of the relevant literature concerning mechanical and multi-physical property modulation of metamaterials focusing on the emerging trend of bi-level design, and subsequently highlight the broad-spectrum potential of mechanical metamaterials in their critical engineering applications. The evolving trends, challenges and future roadmaps have been critically analyzed here involving the notions of real-time reconfigurability and functionality programming, 4D printing, nano-scale metamaterials, artificial intelligence and machine learning, multi-physical origami/kirigami, living matter, soft and conformal metamaterials, manufacturing complex microstructures, service-life effects and scalability.

The history of machine learning (ML) can be traced back to the 1950 s, and its application in alloy design has recently begun to flourish and expand rapidly. The driving force behind this is partially due to the inefficiency of traditional methods in designing better-performing alloys, partially due to the success of ML in other areas and alloy data becoming more accessible. ML methods can quickly predict the properties of the alloy from the data and suggest compositions for particularly required properties, thereby minimizing the need for resource-intensive experiments or simulations. The present work provides a critical review of this domain starting with an introduction to ML components, followed by an overview of the forward prediction of alloy properties, and an elaboration of the inverse design of alloys. This paper aims to summarize crucial findings, reveal key trends, and provide guidance for future directions.

Mechanical metamaterials have been attracting increasing attention for a wide range of industrial applications, such as energy storage, biomedical, sensors, robotics, etc., owing to their artificially-controllable unique mechanical properties beyond those of naturally existing materials. Recently, multimaterial additive manufacturing (AM) techniques, coupled with significant progress made in design methodologies, have accelerated the developments of multiphase mechanical metamaterials advancing the concept to “make the best use of different materials”. To this end, we first review the up-to-date progress of multiphase mechanical metamaterials regarding their design, fabrication processes, unique mechanical properties and applications. Then, we articulate and conclude the major challenges, e.g., interface and connection, uncertainty and inconsistency, among others, for multiphase mechanical metamaterials. Finally, we outline the perspectives of these metamaterials for future key opportunities.

Viruses lacking the capacity to infect mammals exhibit minimal toxicity, good biocompatibility, and well-defined structures. As self-organized biomolecular assemblies, they can be produced from standard biological techniques on a large scale at a low cost. Genetic, chemical, self-assembly, and mineralization techniques have been applied to allow them to display functional peptides or proteins, encapsulate therapeutic drugs and genes, assemble with other materials, and be conjugated with bioactive molecules, enabling them to bear different biochemical properties. So far, a variety of viruses (infecting bacteria, plants, or animals), as well as their particle variants, have been used as biomaterials to advance human disease prevention, diagnosis, and treatment. Specifically, the virus-based biomaterials can serve as multifunctional nanocarriers for targeted therapy, antimicrobial agents for infectious disease treatment, hierarchically structured scaffolds for guiding cellular differentiation and promoting tissue regeneration, versatile platforms for ultrasensitive disease detection, tissue-targeting probes for precision bioimaging, and effective vaccines and immunotherapeutic agents for tackling challenging diseases. This review provides an in-depth discussion of these exciting applications. It also gives an overview of the viruses from materials science perspectives and attempts to correlate the structures, properties, processing, and performance of virus-based biomaterials. It describes the use of virus-based biomaterials for preventing and treating COVID-19 and discusses the challenges and future directions of virus-based biomaterials research. It summarizes the progressive clinical trials of using viruses in humans. With the impressive progress made in the exciting field of virus-based biomaterials, it is clear that viruses are playing key roles in advancing important areas in biomedicine such as early detection and prevention, drug delivery, infectious disease treatment, cancer therapy, nanomedicine, and regenerative medicine.