Materials Science and Engineering: R: Reports最新文献

The exploration and development of natural biopolymer-based hydrogels can be traced back to the 18th century. The rising interest in these hydrogels is largely due to their soaring demand in diverse applications such as tissue engineering, bio-separation, drug delivery, smart bioelectronics, and eco-friendly agriculture. However, one major drawback of these naturally derived biopolymer-based hydrogels is their subpar mechanical properties characterized by limited stretchability, modulus, and resilience, along with inadequate water adsorption capability. This restricts their broad-spectrum applicability. These biopolymers are typically crosslinked through different strategies to rectify these issues and functional groups present in polymer chains play crucial roles in crosslinking strategies. Consequently, the understanding of the chemical structure-function relationship in the crosslinked polymeric network is paramount for the design of an effective natural biopolymer-based hydrogel. A profound comprehension of the behavior of functional groups during crosslinking is therefore essential. This review provides a comprehensive overview of the chemistries of functional group interactions in natural biopolymers that are utilized in the development of functional hydrogels. Various categories of functional group interaction chemistries are examined and discussed in terms of crosslinking strategies (e.g., hydrogen bonding, ionic interaction, hydrophobic interaction) for hydrogel formation. Furthermore, the types, properties, and cutting-edge applications of resultant natural biopolymer-based hydrogels are outlined along with a discussion of the future prospects in this field of research.

In industries as diverse as automotive, aerospace, medical, energy, construction, electronics, and food, the engineering technology known as 3D printing or additive manufacturing facilitates the fabrication of rapid prototypes and the delivery of customized parts. This article explores recent advancements and emerging trends in 3D printing from a novel multidisciplinary perspective. It also provides a clear overview of the various 3D printing techniques used for producing parts and components in three dimensions. The application of these techniques in bioprinting and an up-to-date comprehensive review of their positive and negative aspects are covered, as well as the variety of materials used, with an emphasis on composites, hybrids, and smart materials. This article also provides an updated overview of 4D bioprinting technology, including biomaterial functions, bioprinting materials, and a targeted approach to various tissue engineering and regenerative medicine (TERM) applications. As a foundation for anticipated developments for TERM applications that could be useful for their successful usage in clinical settings, this article also examines present challenges and obstacles in 4D bioprinting technology. Finally, the article also outlines future regulations that will assist researchers in the manufacture of complex products and in the exploration of potential solutions to technological issues.

In the current era of globalization, the exponential surge in the production, consumption, and disposal of agricultural and post-consumer polymeric waste material has emerged as a pressing environmental concern of paramount importance. The current situation, wherein the presence of plastic particles and other plastic-based contaminants in the food supply chain is increasingly evident, poses a profound health risk to mankind. In this regard, the utilization of conventional waste management practices, such as, open burning, landfilling, and incineration, leads to adverse consequences, like, the emission of greenhouse gases and substantial economic losses. To encounter such problems, researchers are actively engaged in the development of innovative recycling processes aimed at closed-loop circular economy by transforming these wastes into sustainable value added products. This comprehensive review emphasizes the necessity of sustainable recycling of lignocellulosic biomass and synthetic plastic wastes, with a specific focus on their transformation into biodegradable polymers and their potential biomedical applications. Moreover, we have critically discussed the recent trends and drivers in this field, global environment threat, different recycling route of lignocellulosic biomass and synthetic polymer wastes. Furthermore, this review provides a detailed discussion on the applications of these biodegradable polymers in the field of tissue engineering, drug delivery, and antimicrobial applications. Additionally, we have also addressed the critical challenges involved in this field and possible solutions to overcome them.

As an important component of future electronic devices, photodetectors require mechanical flexibility, and stretchability to meet the demands of conformal, portable, and lightweight applications. As expected, flexible photodetectors (FPDs) were born timely and have obtained rapid development driven by the considerable progress of the optoelectronic industry. Especially, FPDs appear to serve as a bridge between electronic information systems and biological systems due to their potential functional applications including wearable devices, artificial intelligence, bionics devices, etc. However, the poor mechanical stability, narrow spectral response range, low responsivities and difficulty in miniaturization of traditional FPDs have greatly limited their commercial and industrial applications. One of the most promising routes toward addressing the inherent shortcomings of FPDs is through constructing novel micro/nano-structured integrated flexible detection systems to achieve diverse functions and enhance performance, hence facilitating flexible integration. In this review, the recent advances in performance-enhancing strategies for FPDs are outlined and discussed. First, the detection mechanism, performance enhancement mode, and key figures-of-merit of FPDs are summarized and basic design principles of the FPDs are discussed emphatically. Then, recent progress in structural engineering-based performance enhancement of FPDs is reviewed, categorized by the types of enhancement, electric field manipulation engineering, strain engineering, and optical field manipulation engineering. Moreover, this review also summarizes the integration strategies for the application of FPDs and finally puts forward the challenges and future research directions in these fields.

Ensuring the fire safety of high voltage (HV) outdoor insulators is key to maintain the reliable operation of the electrical grid. This requires the careful selection of suitable polymeric composite materials with excellent electrical tracking, erosion, and fire resistance characteristics. To improve their performance against electrical tracking and potential combustion issues, inorganic additives are commonly integrated into these materials. The focus of this review article is on describing the progress and innovations in enhancing the electrical tracking, erosion, and fire performance of polymeric materials by incorporating inorganic additives. The main objective is to explore the development of these materials and showcase their evaluation through laboratory testing. This study highlights significant state-of-the-art advancements in the field, providing valuable insights into its current progress. Additionally, the research outlines prospects, offering a peek at how upcoming studies are expected to further advance the scientific knowledge in the field. By disseminating critical information about the development, testing, and future potential of polymeric materials containing inorganic additives, this work is expected to facilitate researchers in advancing their work in HV outdoor insulation, leading to more efficient electrical insulation solutions for safer and reliable electrical grids.

Mechanical Metamaterials (MMs) are artificially designed structures with extraordinary properties that are dependent on micro architectures and spatial tessellations of unit cells, rather than constitutive compositions. They have demonstrated promising and attractive application potentials in practical engineering. Recently, how to rationally design novel MMs and discover their multifunctional behaviors has received tremendous discussions with rapid progress, particularly in the last ten years with an enormous increase of publications and citations. Herein, we present a comprehensive overview of considerable advances of MMs, including critical focuses at different scales, forward and inverse design mechanisms with optimization formulations, micro architectures of unit cells, and their spatial tessellations in discovering novel MMs and future prospects. The implications in clarifying the four focuses at levels from the global to the physical in MMs are highlighted, that is, unique structures designed for unique functions, unique micro unit cells placed in unique locations, unique micro unit cells designed for unique properties and unique micro unit cells evaluated by unique mechanisms. We examine the inverse designs of MMs with intrinsic mechanisms of structure-property driven characteristics to achieve unprecedented behaviors, which are involved into material designs and multiscale designs. The former primarily optimizes micro architectures to explore novel MMs, and the latter focuses on micro architectures and spatial tessellations to promote multifunctional applications of MMs in engineering. Finally, we propose several promising research topics with serious challenges in design formulations, micro architectures, spatial tessellations and industrial applications.

Lead halide perovskites with excellent optoelectronic properties have attracted extensive attention and made amazing progress for X-ray detectors and imaging. However, lead is highly toxic to humans, animals and ecosystems, posing a great safety concern to its commercial application. It has become an urgent need to develop stable and environment-friendly lead-free alternatives. In this review, we summarize recent progress in lead-free halide perovskites (LFHPs) and derivatives toward X-ray detectors and imaging. First, we introduce the working principle of X-ray detectors and the key figure of merit in direct and indirect detection processes. In addition, we summarize state-of-the-art lead-free halide perovskites preparation methods. Furthermore, we comprehensively discuss the structural dimensions, optoelectronic properties of lead-free halide perovskites and their recent advances in X-ray detection and imaging. Meanwhile, the stabilities of LFHPs-based X-ray detectors are discussed. Finally, we outline several main issues of state-of-the-art LFHPs-based X-ray detectors and provide prospects to overcome these limitations.

Portable, affordable, and miniaturized electrochemical sensors for point-of-care diagnostic devices represent a step towards achieving the United Nations’ Sustainable Development Goal 3: Good Health and Well-Being. Over the last 10 years, rapid advancements in three-dimensional (3D) printing technology (additive manufacturing) have enabled the production of low-cost, miniature 3D printed (3DP) devices for bio-chemical sensing, enabling innovation in healthcare diagnostics for everyone regardless of their economic background or geographical location. Compared to traditional manufacturing processes, 3D printing offers numerous advantages for miniaturized electrochemical point-of-care diagnostic devices, such as rapid prototyping, custom-shaped devices, flexible fabrication designs, low energy consumption, reduced time to market, and reduced waste generation. This article reviews recent developments in 3DP electrochemical sensors, including the printing of composite materials, advanced electrode architectures, activation and functionalization methods, and electrochemical sensing performance (i.e. sensitivity, linear range, limits of detection) towards various analytes, including heavy metals/water pollutants, toxic/explosive substances, neurotransmitters/stimulants, metabolites, DNA, amino acids, proteins, viruses, and food pathogens. Moreover, we discuss the remaining challenges and gaps in current knowledge and solutions to improve the electroanalytic performance of 3DP electrodes for future biomedical applications in wearable and smart-implantable sensor systems of the future.

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.