Search Results (1,082)

Long-range underwater gliders (LRUGs) have emerged as essential platforms for sustained and autonomous observation in deep and remote marine environments. This paper provides a comprehensive review of their developmental status, performance characteristics, and application progress. Emphasis is placed on two critical enabling technologies that fundamentally determine endurance: lightweight, pressure-resistant hull structures and high-efficiency buoyancy-driven propulsion systems. First, the role of carbon fiber composite pressure hulls in enhancing energy capacity and structural integrity is examined, with attention to material selection, fabrication methods, compressibility compatibility, and antifouling resistance. Second, the evolution of buoyancy control systems is analyzed, covering the transition to hybrid active–passive architectures, rapid-response actuators based on smart materials, thermohaline energy harvesting, and energy recovery mechanisms. Based on this analysis, the paper identifies four key technical challenges and proposes strategic research directions, including the development of ultralight, high-strength structural materials; integrated multi-mechanism antifouling technologies; energy-optimized coordinated buoyancy systems; and thermally adaptive glider platforms. Achieving a system architecture with ultra-long endurance, enhanced energy efficiency, and robust environmental adaptability is anticipated to be a foundational enabler for future long-duration missions and globally distributed underwater glider networks. Full article

This study explores the transformative potential of blockchain technology in overhauling conventional housing rental systems. It specifically addresses persistent issues, such as information asymmetry, fraudulent listings, weak Rental Agreements, and data breaches. A comprehensive review of ten academic publications highlights the architectural frameworks, underlying technologies, and myriad benefits of decentralized rental platforms. The intrinsic characteristics of blockchain—immutability, transparency, and decentralization—are pivotal in enhancing the credibility of rental information and proactively preventing fraudulent activities. Smart contracts emerge as a key innovation, enabling the automated execution of Rental Agreements, thereby significantly boosting efficiency and minimizing reliance on intermediaries. Furthermore, Decentralized Identity (DID) solutions offer a robust mechanism for securely managing identities, effectively mitigating risks associated with data leakage, and fostering a more trustworthy environment. The suitability of platforms such as Hyperledger Fabric for developing such sophisticated rental systems is also critically evaluated. Blockchain-based systems promise to dramatically increase market transparency, bolster transaction security, and enhance fraud prevention. They also offer streamlined processes for dispute resolution. Despite these significant advantages, the widespread adoption of blockchain in the rental sector faces several challenges. These include inherent technological complexity, adoption barriers, the need for extensive legal and regulatory adaptation, and critical privacy concerns (e.g., ensuring compliance with GDPR). Furthermore, blockchain scalability limitations and the intricate balance between data immutability and the necessity for occasional data corrections present considerable hurdles. Future research should focus on developing user-friendly DID solutions, enhancing blockchain performance and cost-efficiency, strengthening smart contract security, optimizing the overall user experience, and exploring seamless integration with emerging technologies. While current challenges are undeniable, blockchain technology offers a powerful suite of tools for fundamentally improving the rental market’s efficiency, transparency, and security, exhibiting significant potential to reshape the entire rental ecosystem. Full article

Gene therapy is a groundbreaking strategy in regenerative medicine, enabling precise cellular behavior modulation for tissue repair. In situ nucleic acid delivery systems aim to directly deliver nucleic acids to target cells or tissues to realize localized genetic reprogramming and avoid issues like donor cell dependency and immune rejection. The key to success relies on biomaterial-engineered delivery platforms that ensure tissue-specific targeting and efficient intracellular transport. Viral vectors and non-viral carriers are strategically modified to enhance nucleic acid stability and cellular uptake, and integrate them into injectable or 3D-printed scaffolds. These scaffolds not only control nucleic acid release but also mimic native extracellular microenvironments to support stem cell recruitment and tissue regeneration. This review explores three key aspects: the mechanisms of gene editing in tissue repair; advancements in viral and non-viral vector engineering; and innovations in biomaterial scaffolds, including stimuli-responsive hydrogels and 3D-printed matrices. We evaluate scaffold fabrication methodologies, nucleic acid loading–release kinetics, and their biological impacts. Despite progress in spatiotemporal gene delivery control, challenges remain in balancing vector biocompatibility, manufacturing scalability, and long-term safety. Future research should focus on multifunctional “smart” scaffolds with CRISPR-based editing tools, multi-stimuli responsiveness, and patient-specific designs. This work systematically integrates the latest methodological advances, outlines actionable strategies for future investigations and advances clinical translation perspectives beyond the existing literature. Full article

The swift advancement of fifth-generation (5G) wireless technology brings forth a range of enhancements to address the increasing demand for data, the proliferation of smart devices, and the growth of the Internet of Things (IoT). This highly interconnected communication environment necessitates using multiple-input multiple-output (MIMO) systems to achieve adequate channel capacity. In this article, a 2-port MIMO system using two flipped parallel 1 × 2 arrays and a 2-port MIMO system using two opposite 1 × 4 arrays designed and fabricated antennas for 5G wireless communication in the sub-6 GHz band, are presented, overcoming the limitations of previous designs in gain, radiation efficiency and MIMO performance. The designed and fabricated single-element antenna features a circular microstrip patch design based on ROGER 5880 (RT5880) substrate, which has a thickness of 1.57 mm, a permittivity of 2.2, and a tangential loss of 0.0009. The 2-port MIMO of two 1 × 2 arrays and the 2-port MIMO of two 1 × 4 arrays have overall dimensions of 132 × 66 × 1.57 mm³ and 140 × 132 × 1.57 mm³, respectively. The MIMO of two 1 × 2 arrays and MIMO of two 1 × 4 arrays encompass maximum gains of 8.3 dBi and 10.9 dBi, respectively, with maximum radiation efficiency reaching 95% and 97.46%. High MIMO performance outcomes are observed for both the MIMO of two 1 × 2 arrays and the MIMO of two 1 × 4 arrays, with the channel capacity loss (CCL) ˂ 0.4 bit/s/Hz and ˂0.3 bit/s/Hz, respectively, an envelope correlation coefficient (ECC) ˂ 0.006 and ˂0.003, respectively, directivity gain (DG) about 10 dB, and a total active reflection coefficient (TARC) under −10 dB, ensuring impedance matching and effective mutual coupling among neighboring parameters, which confirms their effectiveness for 5G applications. The three fabricated antennas were experimentally tested and implemented using the MIMO Application Framework version 19.5 for 5G systems, demonstrating operational effectiveness in 5G applications. Full article

Photoelectrochemical devices have garnered extensive research attention in the field of smart and multifunctional photoelectronics, owing to their lightweight nature, eco-friendliness, and cost-effective manufacturing processes. In this work, Bi₂S₃/Bi₂O₃/TiO₂ heterojunction film was successfully fabricated and functioned as the photoelectrode of photoelectrochemical devices. The designed Bi₂S₃/Bi₂O₃/TiO₂ photoelectrochemical photodetector possesses a broad light detection spectrum ranging from 400 to 900 nm and impressive self-powered characteristics. At 0 V bias, the device exhibits an on/off current ratio of approximately 1.3 × 10⁶. It achieves a commendable detectivity of 5.7 × 10¹³ Jones as subjected to a 0.8 V bias potential, outperforming both bare TiO₂ and Bi₂O₃/TiO₂ photoelectrochemical devices. Moreover, the Bi₂S₃/Bi₂O₃/TiO₂ photoelectrode film shows great promise in pollutant decomposition, achieving nearly 97.7% degradation efficiency within 60 min. The appropriate band energy alignment and the presence of an internal electric field at the interface of the Bi₂S₃/Bi₂O₃/TiO₂ film serve as a potent driving force for the separation and transport of photogenerated carriers. These findings suggest that the Bi₂S₃/Bi₂O₃/TiO₂ heterojunction film could be a viable candidate as a photoelectrode material for the development of high-performance photoelectrochemical optoelectronic devices. Full article

The blockchain technology is transforming the mining industry by enabling mineral reserve tokenization, improving security, transparency, and traceability. However, controlling access to sensitive mining data remains a challenge. Existing access control models, such as role-based access control, are too rigid because they assign permissions based on predefined roles rather than real-world conditions like mining licenses, regulatory approvals, or investment status. To address this, this paper explores an attribute-based access control model for blockchain-based mineral tokenization systems. ABAC allows access permissions to be granted dynamically based on multiple attributes rather than fixed roles, making it more adaptable to the mining industry. This paper presents a high-level system design that integrates ABAC with the blockchain using smart contracts to manage access policies and ensure compliance. The proposed model is designed for permissioned blockchain platforms, where access control decisions can be automated and securely recorded. A comparative analysis between ABAC and RBAC highlights how ABAC provides greater flexibility, security, and privacy for mining operations. By introducing ABAC in blockchain-based mineral reserve tokenization, this paper contributes to a more efficient and secure way of managing data access in the mining industry, ensuring that only authorized stakeholders can interact with tokenized mineral assets. Full article

In the rapidly evolving field of biomedical engineering, hydrogels have emerged as highly versatile biomaterials that bridge biology and technology through their high water content, exceptional biocompatibility, and tunable mechanical properties. This review provides an integrated overview of both natural and synthetic hydrogels, examining their structural properties, fabrication methods, and broad biomedical applications, including drug delivery systems, tissue engineering, wound healing, and regenerative medicine. Natural hydrogels derived from sources such as alginate, gelatin, and chitosan are highlighted for their biodegradability and biocompatibility, though often limited by poor mechanical strength and batch variability. Conversely, synthetic hydrogels offer precise control over physical and chemical characteristics via advanced polymer chemistry, enabling customization for specific biomedical functions, yet may present challenges related to bioactivity and degradability. The review also explores intelligent hydrogel systems with stimuli-responsive and bioactive functionalities, emphasizing their role in next-generation healthcare solutions. In modern medicine, temperature-, pH-, enzyme-, light-, electric field-, magnetic field-, and glucose-responsive hydrogels are among the most promising “smart materials”. Their ability to respond to biological signals makes them uniquely suited for next-generation therapeutics, from responsive drug systems to adaptive tissue scaffolds. Key challenges such as scalability, clinical translation, and regulatory approval are discussed, underscoring the need for interdisciplinary collaboration and continued innovation. Overall, this review fosters a comprehensive understanding of hydrogel technologies and their transformative potential in enhancing patient care through advanced, adaptable, and responsive biomaterial systems. Full article

Marine biomass represents a valuable yet underexploited resource for the development of high-value biomaterials. Recent advances have highlighted the significant potential of marine-derived polysaccharides, proteins, and peptides in biomedical applications, most notably in drug delivery and wound healing. This review provides a comprehensive synthesis of current research on the extraction, processing and pharmaceutical valorization of these biopolymers, with a focus on their structural and functional properties that allow these materials to be engineered into nanocarriers, hydrogels, scaffolds, and smart composites. Key fabrication strategies such as ionic gelation, desolvation, and 3D bioprinting are critically examined for their role in drug encapsulation, release modulation, and scaffold design for regenerative therapies. The review also covers preclinical validation, scale-up challenges, and relevant regulatory frameworks, offering a practical roadmap from sustainable sourcing to clinical application. Special attention is given to emerging technologies, including stimuli-responsive biomaterials and biosensor-integrated wound dressings, as well as to the ethical and environmental implications of marine biopolymer sourcing. By integrating materials science, pharmaceutical technology and regulatory insight, this review aims to provide a multidisciplinary perspective for researchers and industrial stakeholders seeking sustainable and multifunctional pharmaceutical platforms for precision medicine and regenerative therapeutics. Full article

Graphene has emerged as a promising material for transforming conventional textiles into smart, multi-functional platforms due to its exceptional electrical, thermal, and mechanical properties. This review aims to provide a comprehensive overview of the latest advances in graphene-enhanced fabrics over the past ten years, focusing on their functional properties and real-world applications. This article examines the main strategies used to incorporate graphene and its derivatives—such as graphene oxide and reduced graphene oxide—into textile substrates through coating, printing, or composite formation. The structural, electrical, thermal, mechanical, and electrochemical properties of these fabrics are discussed based on characterization techniques including microscopy, Raman spectroscopy, and cyclic voltammetry. Functional evaluations in wearable strain sensors, biosignal acquisition, electrothermal systems, and energy storage devices are highlighted to demonstrate the versatility of these materials. Although challenges remain in scalability, durability, and washability, recent developments in fabrication and encapsulation methods show significant potential to overcome these limitations. This review concludes by outlining the major opportunities and future directions for graphene-based textiles in areas such as personalized health monitoring, active thermal wear, and integrated wearable electronics. Full article

Hydrogels have emerged as multifunctional biomaterials in cardiac surgery, offering promising solutions for myocardial regeneration, adhesion prevention, valve engineering, and localized drug and gene delivery. Their high water content, biocompatibility, and mechanical tunability enable close emulation of the cardiac extracellular matrix, supporting cellular viability and integration under dynamic physiological conditions. In myocardial repair, injectable and patch-forming hydrogels have been shown to be effective in reducing infarct size, promoting angiogenesis, and preserving contractile function. Hydrogel coatings and films have been designed as adhesion barriers to minimize pericardial adhesions after cardiotomy and improve reoperative safety. In heart valve and patch engineering, hydrogels contribute to scaffold design by providing bio-instructive, mechanically resilient, and printable matrices that are compatible with 3D fabrication. Furthermore, hydrogels serve as localized delivery platforms for small molecules, proteins, and nucleic acids, enabling sustained or stimuli-responsive release while minimizing systemic toxicity. Despite these advances, challenges such as mechanical durability, immune compatibility, and translational scalability persist. Ongoing innovations in smart polymer chemistry, hybrid composite design, and patient-specific manufacturing are addressing these limitations. This review aims to provide an integrated perspective on the application of hydrogels in cardiac surgery. The relevant literature was identified through a narrative search of PubMed, Scopus, Web of Science, Embase, and Google Scholar. Taken together, hydrogels offer a uniquely versatile and clinically translatable platform for addressing the multifaceted challenges of cardiac surgery. Hydrogels are poised to redefine clinical strategies in cardiac surgery by enabling tailored, bioresponsive, and functionally integrated therapies. Full article

Phase-change microcapsules offer significant advantages for thermal energy storage and regulation. However, conventional mechanical agitation fabrication methods encounter difficulties in achieving monodispersity, precise size control, and structural uniformity. Droplet microfluidics emerges as a promising alternative, enabling controllable production of microcapsules with tunable sizes (1–1000 μm), programmable core–shell configurations, and high encapsulation efficiency. This review comprehensively summarizes recent advances in microfluidic strategies for phase-change microcapsules fabricating, including single encapsulation, multi-core encapsulation, and high-throughput parallelization and their applications in solar energy storage, building thermal regulation, electronics cooling, and smart textiles. The review highlights key challenges for future advancement which will unlock the full potential of microfluidics-engineered phase-change microcapsules in next-generation thermal energy technologies. Full article

In modern wireless communication systems, achieving high isolation and consistent signal gain is essential for optimizing Multiple-Input Multiple-Output (MIMO) antenna performance. This study presents a metamaterial-integrated smart sensor platform featuring a hexagonal two-element MIMO antenna designed to improve isolation and directive gain. Constructed on an FR4 substrate (1.6 mm thick), the proposed antenna configurations include a base hexagonal patch, an orthogonally oriented two-element system (TEH_OC), and further enhanced variants employing metamaterial arrays as the superstrate and reflector (TEH_OC_MTS and TEH_OC_MTR). The metamaterial structures significantly suppress mutual coupling, yielding superior diversity parameters such as Envelope Correlation Coefficient (ECC), Mean Effective Gain (MEG), and Channel Capacity Loss (CCL). All configurations were fabricated and validated through comprehensive anechoic chamber measurements. The results demonstrate robust isolation and radiation performance across the 3 GHz and 5 GHz bands, making these antennas well-suited for deployment in compact, low-latency smart sensor networks operating in 5G and IoT environments. Full article

Planar heaters are designed to deliver uniform heat across broad surfaces and serve as critical components in applications requiring energy efficiency, safety, and mechanical flexibility, such as wearable electronics and smart textiles. However, conventional metal-based heaters are limited by poor adaptability to curved or complex surfaces, low mechanical compliance, and susceptibility to oxidation-induced degradation. To overcome these challenges, we applied a protein-assisted electroless copper (Cu) plating strategy to electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber substrates to fabricate flexible, conductive planar heating membranes. For interfacial functionalization, a protein-based engineering approach using bovine serum albumin (BSA) was employed to facilitate palladium ion coordination and seed formation. The resulting membrane exhibited a dense, continuous Cu coating, low sheet resistance, excellent durability under mechanical deformation, and stable heating performance at low voltages. These results demonstrate that the BSA-assisted strategy can be effectively extended to complex three-dimensional fibrous membranes, supporting its scalability and practical potential for next-generation conformal and wearable planar heaters. Full article

Recent advancements in polymer science have catalyzed a transformative shift in biomedical engineering, particularly through the development of biodegradable and smart polymers. This review explores the evolution, functionality, and application of these materials in areas such as tissue scaffolding, cardiovascular occluders, and controlled drug delivery systems. Emphasis is placed on shape-memory polymers (SMPs), conductive polymers, and polymer-based composites that combine tunable degradation, mechanical strength, and bioactivity. The synergy between natural and synthetic polymers—augmented by nanotechnology and additive manufacturing—enables the creation of intelligent scaffolds and implantable devices tailored for specific clinical needs. Key fabrication methods, including electrospinning, freeze-drying, and emulsion-based techniques, are discussed in relation to pore structure and functionalization strategies. Finally, the review highlights emerging trends, including ionic doping, 3D printing, and multifunctional nanocarriers, outlining their roles in the future of regenerative medicine and personalized therapeutics. Full article

Background/Objectives: The introduction of composite attachments has greatly improved orthodontic aligner therapy, through better force delivery, more predictable movements, and enhanced retention. This in vitro study aims to present and investigate an innovative digital protocol for aligner attachment fabrication incorporating the latest 3D technology used in dentistry. Methods: A virtual attachment measuring 2.5 × 2 × 2 mm was designed using computer-aided design (CAD) software (Meshmixer, Autodesk Inc., San Francisco, CA, USA) and exported as an individual STL file. The attachments were fabricated using a digital light processing (DLP) 3D printer (model: Elegoo 4 DLP, Shenzhen, China) and a dental-grade biocompatible resin. A custom 3D-printed placement guide was used to ensure precise positioning of the attachments on the printed maxillary dental models. A flowable resin was applied to secure the attachments in place. Following attachment placement, the models were scanned using a laboratory desktop scanner (Optical 3D Smart Big, Open Technologies, Milano, Italy) and three intraoral scanners: iTero Element (Align Technology, Tempe, AZ, USA), Aoral 2, and Aoral 3 (Shining 3D, Hangzhou, China). Results: Upon comparison, the scans revealed that the iTero Element exhibited the highest precision, particularly in the attachment, with an RMSE of 0.022 mm and 95.04% of measurements falling within a ±100 µm tolerance. The Aoral 2 scanner showed greater variability, with the highest RMSE (0.041 mm) in the incisor area and wider deviation margins. Despite this, all scanners produced results within clinically acceptable limits. Conclusions: In the future, custom attachments made by 3D printing could be a valid alternative to the traditional composite attachments when it comes to improving aligner attachment production. While these preliminary findings support the potential applicability of such workflows, further in vivo research is necessary to confirm clinical usability. Full article