Explore the vast range of titles available.

This research investigates the critical role of frequency selection in Electrical Impedance Tomography (EIT), a non-invasive imaging technique that reconstructs internal conductivity distributions through injected electrical currents. Empirical frequency selection is paramount to maximizing the fidelity and specificity of EIT images. The study explores the impact of distinct frequency ranges—low, medium, and high—on image contrast and clarity, particularly focusing on differentiating conductive materials from non-conductive materials. The findings reveal distinct empirical frequency bands for enhancing the respective contrasts: 15–38 kHz for conductive materials (copper) and 45–75 kHz for non-conductive materials (acrylic resin). These insights shed light on the frequency-dependent nature of material contrast in EIT images, guiding the selection of empirical operating ranges for various target materials. This research paves the way for improved sensitivity and broader applicability of EIT in diverse areas.

The anaerobic digestion (AD) of organic matter is susceptible to the challenges posed by low-speed electron transfer between microorganisms and the limitation of low hydrogen partial pressure, resulting in low methane recovery efficiency and poor system stability. Numerous studies in recent years have shown that a variety of conductive materials can significantly increase the interspecies electron transfer (IET) rate, optimize the structure and function of anaerobic microbial communities, improve methane yield, and promote system stability by mediating the direct interspecies electron transfer (DIET) of reciprocal microorganisms. In this study, on the basis of investigating the IET mechanism of methanogenic microorganisms in the AD of organic matter, the effects of carbon-based conductive materials (activated carbon, biochar, carbon cloth, carbon fiber, graphite, graphite felt, graphene, and carbon nanotubes) and iron-based conductive materials (magnetite, Fe3O4, hematite, Fe2O3, goethite, and zero-valent iron) on AD performance and microbial community using DIET are reviewed. Future research should focus on establishing an evaluation system, identifying flora with DIET potential, and finding methods for engineering applications that increase recovery efficiency and reveal the principle of conductive materials to mediate DIET.

In the last three decades, the development of new kinds of textiles, so-called smart and interactive textiles, has continued unabated. Smart textile materials and their applications are set to drastically boom as the demand for these textiles has been increasing by the emergence of new fibers, new fabrics, and innovative processing technologies. Moreover, people are eagerly demanding washable, flexible, lightweight, and robust e-textiles. These features depend on the properties of the starting material, the post-treatment, and the integration techniques. In this work, a comprehensive review has been conducted on the integration techniques of conductive materials in and onto a textile structure. The review showed that an e-textile can be developed by applying a conductive component on the surface of a textile substrate via plating, printing, coating, and other surface techniques, or by producing a textile substrate from metals and inherently conductive polymers via the creation of fibers and construction of yarns and fabrics with these. In addition, conductive filament fibers or yarns can be also integrated into conventional textile substrates during the fabrication like braiding, weaving, and knitting or as a post-fabrication of the textile fabric via embroidering. Additionally, layer-by-layer 3D printing of the entire smart textile components is possible, and the concept of 4D could play a significant role in advancing the status of smart textiles to a new level.

Anaerobic digestion (AD) is an effective biological treatment for stabilizing organic compounds in waste/wastewater and in simultaneously producing biogas. However, it is often limited by the slow reaction rates of different microorganisms’ syntrophic biological metabolisms. Stable and fast interspecies electron transfer (IET) between volatile fatty acid-oxidizing bacteria and hydrogenotrophic methanogens is crucial for efficient methanogenesis. In this syntrophic interaction, electrons are exchanged via redox mediators such as hydrogen and formate. Recently, direct IET (DIET) has been revealed as an important IET route for AD. Microorganisms undergoing DIET form interspecies electrical connections via membrane-associated cytochromes and conductive pili; thus, redox mediators are not required for electron exchange. This indicates that DIET is more thermodynamically favorable than indirect IET. Recent studies have shown that conductive materials (e.g., iron oxides, activated carbon, biochar, and carbon fibers) can mediate direct electrical connections for DIET. Microorganisms attach to conductive materials’ surfaces or vice versa according to particle size, and form conductive biofilms or aggregates. Different conductive materials promote DIET and improve AD performance in digesters treating different feedstocks, potentially suggesting a new approach to enhancing AD performance. This review discusses the role and potential of DIET in methanogenic systems, especially with conductive materials for promoting DIET.

HighlightsGeneral principles for fiber functionalization and strain sensor fabrication are briefly reviewed.Future application potentials of wearable strain sensors are summarized and evaluated.Challenges and perspectives of fiber-based wearable strain sensors are critically discussed.Wearable strain sensors are arousing increasing research interests in recent years on account of their potentials in motion detection, personal and public healthcare, future entertainment, man–machine interaction, artificial intelligence, and so forth. Much research has focused on fiber-based sensors due to the appealing performance of fibers, including processing flexibility, wearing comfortability, outstanding lifetime and serviceability, low-cost and large-scale capacity. Herein, we review the latest advances in functionalization and device fabrication of fiber materials toward applications in fiber-based wearable strain sensors. We describe the approaches for preparing conductive fibers such as spinning, surface modification, and structural transformation. We also introduce the fabrication and sensing mechanisms of state-of-the-art sensors and analyze their merits and demerits. The applications toward motion detection, healthcare, man–machine interaction, future entertainment, and multifunctional sensing are summarized with typical examples. We finally critically analyze tough challenges and future remarks of fiber-based strain sensors, aiming to implement them in real applications.

HighlightsThe state-of-the-art progress of flexible thermally conductive films with ultrahigh in-plane isotropic thermal conductivity (k) and potential application are summarized.The heat transfer mechanism, processing methods to enhance k, optimization strategies to reduce interface thermal resistance of flexible thermally conductive films are reviewed.The limitations and opportunities for the future development of flexible thermally conductive films are proposed.Effective thermal management is quite urgent for electronics owing to their ever-growing integration degree, operation frequency and power density, and the main strategy of thermal management is to remove excess energy from electronics to outside by thermal conductive materials. Compared to the conventional thermal management materials, flexible thermally conductive films with high in-plane thermal conductivity, as emerging candidates, have aroused greater interest in the last decade, which show great potential in thermal management applications of next-generation devices. However, a comprehensive review of flexible thermally conductive films is rarely reported. Thus, we review recent advances of both intrinsic polymer films and polymer-based composite films with ultrahigh in-plane thermal conductivity, with deep understandings of heat transfer mechanism, processing methods to enhance thermal conductivity, optimization strategies to reduce interface thermal resistance and their potential applications. Lastly, challenges and opportunities for the future development of flexible thermally conductive films are also discussed.

Tissue engineering endeavors to regenerate tissues and organs through appropriate cellular and molecular interactions at biological interfaces. To this aim, bio-mimicking scaffolds have been designed and practiced to regenerate and repair dysfunctional tissues by modifying cellular activity. Cellular activity and intracellular signaling are performances given to a tissue as a result of the function of elaborated electrically conductive materials. In some cases, conductive materials have exhibited antibacterial properties; moreover, such materials can be utilized for on-demand drug release. Various types of materials ranging from polymers to ceramics and metals have been utilized as parts of conductive tissue engineering scaffolds, having conductivity assortments from a range of semi-conductive to conductive. The cellular and molecular activity can also be affected by the microstructure; therefore, the fabrication methods should be evaluated along with an appropriate selection of conductive materials. This review aims to address the research progress toward the use of electrically conductive materials for the modulation of cellular response at the material-tissue interface for tissue engineering applications.

HighlightsA core–sheath structured phase change nanocomposite (PCN) with aligned and overlapping interconnected BNNS networks were successfully fabricated.The PCN has an ultrahigh in-plane thermal conductivity (28.3 W m−1 K−1), excellent flexibility and high phase change enthalpy (101 J g−1).The PCN exhibits intensively potential applications in the thermal management of 5G base stations and thermoelectric generators.Thermal management has become a crucial problem for high-power-density equipment and devices. Phase change materials (PCMs) have great prospects in thermal management applications because of their large capacity of heat storage and isothermal behavior during phase transition. However, low intrinsic thermal conductivity, ease of leakage, and lack of flexibility severely limit their applications. Solving one of these problems often comes at the expense of other performance of the PCMs. In this work, we report core–sheath structured phase change nanocomposites (PCNs) with an aligned and interconnected boron nitride nanosheet network by combining coaxial electrospinning, electrostatic spraying, and hot-pressing. The advanced PCN films exhibit an ultrahigh thermal conductivity of 28.3 W m−1 K−1 at a low BNNS loading (i.e., 32 wt%), which thereby endows the PCNs with high enthalpy (> 101 J g−1), outstanding ductility (> 40%) and improved fire retardancy. Therefore, our core–sheath strategies successfully balance the trade-off between thermal conductivity, flexibility, and phase change enthalpy of PCMs. Further, the PCNs provide powerful cooling solutions on 5G base station chips and thermoelectric generators, displaying promising thermal management applications on high-power-density equipment and thermoelectric conversion devices.

HighlightsFundamental principles for designing high-performance thermally conductive graphene-based polymer composites are reviewed in detail.The reasoning behind using the preconstructed graphene 3D networks for fabricating thermally conductive composites and recent progress are discussed in-depth.Insight into the existing bottlenecks and opportunities in developing preconstructed 3D networks of graphene and their thermally conductive composites is also presented.Electronic devices generate heat during operation and require efficient thermal management to extend the lifetime and prevent performance degradation. Featured by its exceptional thermal conductivity, graphene is an ideal functional filler for fabricating thermally conductive polymer composites to provide efficient thermal management. Extensive studies have been focusing on constructing graphene networks in polymer composites to achieve high thermal conductivities. Compared with conventional composite fabrications by directly mixing graphene with polymers, preconstruction of three-dimensional graphene networks followed by backfilling polymers represents a promising way to produce composites with higher performances, enabling high manufacturing flexibility and controllability. In this review, we first summarize the factors that affect thermal conductivity of graphene composites and strategies for fabricating highly thermally conductive graphene/polymer composites. Subsequently, we give the reasoning behind using preconstructed three-dimensional graphene networks for fabricating thermally conductive polymer composites and highlight their potential applications. Finally, our insight into the existing bottlenecks and opportunities is provided for developing preconstructed porous architectures of graphene and their thermally conductive composites.

HighlightsThis article systematically reviews the thermal management wearables with a specific emphasis on materials and strategies to regulate the human body temperature.Thermal management wearables are subdivided into the active and passive thermal managing methods.The strength and weakness of each thermal regulatory wearables are discussed in details from the view point of practical usage in real-life.Thermal management is essential in our body as it affects various bodily functions, ranging from thermal discomfort to serious organ failures, as an example of the worst-case scenario. There have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body, employing diverse materials and systematic approaches to attaining thermal homeostasis. This paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables, particularly emphasizing the strategic methodology to regulate body temperature. There exist several methods to promote personal thermal management in a wearable form. For instance, we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin surface. Thus, we classify many studies into two branches, passive and active thermal management modes, which are further subdivided into specific strategies. Apart from discussing the strategies and their mechanisms, we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.