Search Results (61)

Enhancing the thermal performance of building façades is vital for reducing energy demand in hot desert climates, where envelope heat gain increases cooling loads. This study investigates the integration of biomimicry into opaque ventilated façade (OVF) systems as a novel approach to reduce façade surface temperatures. Thirteen bio-inspired façade configurations, modeled after strategies observed in nature, were evaluated using computational fluid dynamics simulations to assess their effectiveness in increasing airflow and reducing inner skin surface temperatures. Results show that all proposed biomimetic solutions outperformed the baseline OVF in terms of thermal performance, with the wide top mound configuration achieving the greatest temperature reduction—up to 5.9 °C below the baseline OVF and 16.4 °C below an unventilated façade. The study introduces an innovative methodology that derives façade design parameters from nature and validates them through simulation. These findings highlight the potential of nature-based solutions to improve building envelope performance in extreme climates. Full article

The results of radiotherapy in patients with primary malignant brain tumors are extremely dissatisfactory: the overall survival after a diagnosis of glioblastoma is typically less than three years. The development of spatially fractionated radiotherapy techniques could help to improve this bleak prognosis. In order to develop technical equipment and organ-specific therapy plans, dosimetry studies as well as radiobiology studies are conducted. Although perfect spheres are considered optimal phantoms by physicists, this does not reflect the wide variety of head sizes and shapes in our patient community. Depth from surface and X-ray dose absorption by tissue between dose entry point and target, two key parameters in medical physics planning, are largely determined by the shape and thickness of the skull bone. We have, therefore, designed and produced a biomimetic tool to correlate measured technical dose and biological response in human cancer cells: a brain phantom, produced from tissue-equivalent materials. In a first pilot study, utilizing our phantom to correlate technical dose measurements and metabolic response to radiation in human cancer cell lines, we demonstrate why an anthropomorphic phantom is preferable over a simple spheroid phantom. Full article

Cell membranes are vital for living organisms and serve as a dynamic barrier between the internal and external environments. They are composed of a complex lipid bilayer embedded with proteins, allowing them to perform multiple functions like maintaining the cell structure, regulating which substances enter or leave the cell, and intercellular communication. Cellular functions are inherently linked to their membrane properties, and the heterogeneous nature of cell membranes makes the study of their physico-chemical properties extremely challenging. This review is intended to provide a comprehensive overview of the composition and physical features of the cell membrane, by focusing on the lipid and protein composition, and on the physical properties (like membrane stiffness or fluidity), highlighting how these characteristics influence cell functions. An insight into the similarities and differences from the membranes of extracellular vesicles (naturally secreted by almost all cell types) is also provided. The understanding of the physico-chemical properties of cell membranes might find application in different therapeutic fields, like disease diagnosis and development of novel drug delivery systems. Therefore, an overview of the literature works describing the rational design of biomimetic drug delivery systems is presented, focusing on the choice of lipid components, frequently inspired by the study of the composition of naturally secreted exosomes, and on the physical characterization of the systems. In the future, in-depth study of biologic vesicles might lead to the development of promising formulation for drug delivery, possibly enhancing the therapeutic outcomes of many pathologies, like cancer. Full article

Advanced gas turbine cooling technologies are required to bridge the gap between turbine inlet temperatures and component thermal limits. Transpiration cooling has emerged as a promising method, leveraging porous structures to enhance cooling effectiveness. Recent advancements in additive manufacturing (AM) enable precise fabrication of complex transpiration cooling architectures, such as triply periodic minimal surface (TPMS) and biomimetic designs. This review analyzes AM-enabled transpiration cooling for gas turbines, elucidating key parameters, heat transfer mechanisms, and flow characteristics of AM-fabricated designs through experimental and numerical studies. Previous research has concluded that well-designed transpiration cooling achieves cooling effectiveness up to five times higher than the traditional film cooling methods, minimizes jet lift-off, improves temperature uniformity, and reduces coolant requirements. Optimized coolant controls, graded porosity designs, complex topologies, and hybrid cooling architectures further enhance the flow uniformity and cooling effectiveness in AM transpiration cooling. However, challenges remain, including 4–77% porosity shrinkage in perforated transpiration cooling for 0.5–0.06 mm holes, 15% permeability loss from defects, and 10% strength reduction in AM models. Emerging solutions include experimental validations using advanced diagnostics, high-fidelity multiphysics simulations, AI-driven and topology optimizations, and novel AM techniques, which aim at revolutionizing transpiration cooling for next-generation gas turbines operating under extreme conditions. Full article

Membrane technologies are used in the production of potable water and the treatment of wastewater in the military forces, providing the highest level of contaminant removal at an energy-efficient cost. This review examines the integration and application of membrane technologies, including reverse osmosis, nanofiltration, ultrafiltration, electrodialysis and advanced hybrid systems, in the treatment of wastewater generated at military bases, naval vessels and submarines. Special emphasis is placed on purification technologies for chemically, biologically and radiologically contaminated wastewater, as well as on the recycling and treatment of wastewater streams by mobile systems used in military applications. Given the specific requirements of complex military infrastructures, particularly in terms of energy efficiency, unit self-sufficiency and reduced dependence on logistical supply chains, this work analyses the latest advances in membrane technologies. Innovations such as nanographene membranes, biomimetic membranes, antifouling membrane systems and hybrid configurations of forward osmosis/reverse osmosis and electrodialysis/reverse electrodialysis offer unique potential for implementation in modular and mobile water treatment systems. In addition, the integration and operational use of these advanced technologies serve as a foundation for the development of autonomous military water supply strategies tailored to extreme operational conditions. The continued advancement and optimization of membrane technologies in military contexts is expected to significantly impact operational sustainability while minimizing environmental impact. Full article

This study presents a novel approach to fabricating magnetic sponge-like composites by melting various types of steel onto three-dimensional (3D) carbonized spongin scaffolds under extreme biomimetic conditions. Spongin, a renewable marine biopolymer with high thermal stability, was carbonized at 1200 °C to form a turbostratic graphite matrix capable of withstanding the high-temperature steel melting process (1450–1600 °C). The interaction between molten steel vapors and the carbonized scaffolds resulted in the formation of nanostructured iron oxide (primarily hematite) coatings, which impart magnetic properties to the resulting composites. Detailed characterization using SEM-EDX, HRTEM, FT-IR, and XRD confirmed the homogeneous distribution of iron oxides on and within the carbonized fibrous matrix. Electrochemical measurements further demonstrated the electrocatalytic potential of the composite, particularly the sample modified with stainless steel 316L—for the hydrogen evolution reaction (HER), offering promising perspectives for green hydrogen production. This work highlights the potential of extreme biomimetics to create functional, scalable, and sustainable materials for applications in catalysis, environmental remediation, and energy technologies. Full article

This study introduces an innovative annular sealing groove design inspired by the hierarchical structure of octopus suckers, addressing the limitations of conventional seals under extreme conditions in aerospace engineering. Using finite element analysis, eight bionic configurations with varying groove parameters (width, depth, number) were systematically evaluated under cryogenic (−196.25 °C) and high-pressure (2 MPa) scenarios. Results show that the optimized bionic6 configuration (seven grooves, 0.4 mm width, 0.4 mm depth) achieved a 21.71% improvement in average von Mises stress compared to the original design, demonstrating enhanced leakage resistance. Parameter interaction analysis revealed groove number as the most significant factor affecting performance, followed by width, while depth showed minimal influence. The hierarchical groove architecture effectively mimicked the multi-level sealing mechanism of octopus suckers, reducing leakage paths and improving adaptability to irregular surfaces. This work bridges biological inspiration and engineering application, providing a scalable solution for extreme environments. The identified optimal parameters lay a theoretical foundation for designing high-performance seals in aerospace, cryogenic storage, and advanced manufacturing. Full article

Background/Objectives: Minor amputations are increasingly relevant due to a growing proportion of lower limb amputations but remain underrepresented in research. These amputations impair mobility due to altered gait, and biomimetic devices could potentially address this issue. Fundamental research is needed to better understand this pathological gait pattern. The aim of this study is to analyse the holistic gait characteristics of the lower extremity during barefoot walking in individuals with different levels of minor amputations for the first time. Methods: Eight young to middle-aged subjects with minor foot amputations (four × hallux; four × forefoot) underwent instrumented gait analysis. Kinematic and kinetic data were acquired barefoot at self-selected gait speeds. Individual gait characteristics were considered relative to the physiological gait represented by the 95% confidence interval of ten unimpaired volunteers. Results: Subjects with a minor amputation show reduced walking speed and shorter stride length compared to controls. Sagittal ankle moment and ankle power are lower, with greater deficits in subjects with a forefoot amputation. Proximal joints also show variability, notably reduced knee flexion in subjects with a forefoot amputation and a more flexed hip profile in six subjects. Single-subject frontal plane kinetics also vary. Conclusions: Although the subjects with a hallux amputation exhibit smaller deviations in ankle kinetics than the subjects with a forefoot amputation, proximal joint abnormalities are present across cases. These findings highlight the need for a broad range of care to adequately address individual needs. Full article

Gas embolism is a rare but life-threatening process characterized by the presence of gas bubbles in the venous or arterial systems. These bubbles, if sufficiently large or numerous, can block the delivery of oxygen to critical organs, in particular the brain, and subsequently they can trigger a cascade of adverse biochemical reactions with severe medical outcomes. Despite its critical nature, gas embolism remains poorly understood, necessitating extensive investigation, particularly regarding its manifestations in the human body and its modulation by various biological conditions. However, given its elusive nature, as well as potential lethality, gas embolism is extremely difficult to study in vivo, and nearly impossible to be the subject of clinical trials. To this end, we developed a microfluidic device designed to study in vitro the impact of blood properties and vascular geometries on the formation and evolution of gas bubbles. The system features a biomimetic vascular channel surrounded by two pressure chambers, which induce the genesis of bubbles under varying circumstances. The bubble parameters were correlated with different input parameters, i.e., channel widths, wall thicknesses, viscosities of the artificial blood, and pressure levels. Smaller channel widths and higher equivalent hematocrit concentrations in synthetic blood solutions increased the nucleation density and bubble generation frequencies. Small channel widths were also more prone to bubble formation, with implications for the vulnerability of vascular walls, leading to increased risks of damage or compromise to the integrity of the blood vessels. Larger channel widths, along with higher equivalent hematocrit concentrations, translated into larger bubble volumes and decreased bubble velocities, leading to an increased risk of bubble immobilization within the blood vessels. This biomimetic approach provides insights into the impact of patient history and biological factors on the incidence and progression of gas embolism. Medical conditions, such as anemia, along with anatomical features related to age and sex—such as smaller blood vessels in women and children or larger vascular widths in adult men—affect the susceptibility to the initiation and progression of gas embolism, explored here in vitro through the development of a controlled, physiological-like environment. The analysis of the videos that recorded gas embolism events in vitro for systems where pressure is applied laterally on the microvasculature with thin walls, i.e., 50 μm or less, suggests that the mechanism of gas transfer for the pressure area to the blood is based on percolation, rather than diffusion. These findings highlight the importance of personalized approaches in the management and prevention of gas embolism. Full article

Speech emotion recognition (SER) tasks are conducted to extract emotional features from speech signals. The characteristic parameters are analyzed, and the speech emotional states are judged. At present, SER is an important aspect of artificial psychology and artificial intelligence, as it is widely implemented in many applications in the human–computer interface, medical, and entertainment fields. In this work, six transforms, namely, the synchrosqueezing transform, fractional Stockwell transform (FST), K-sine transform-dependent integrated system (KSTDIS), flexible analytic wavelet transform (FAWT), chirplet transform, and superlet transform, are initially applied to speech emotion signals. Once the transforms are applied and the features are extracted, the essential features are selected using three techniques: the Overlapping Information Feature Selection (OIFS) technique followed by two biomimetic intelligence-based optimization techniques, namely, Harris Hawks Optimization (HHO) and the Chameleon Swarm Algorithm (CSA). The selected features are then classified with the help of ten basic machine learning classifiers, with special emphasis given to the extreme learning machine (ELM) and twin extreme learning machine (TELM) classifiers. An experiment is conducted on four publicly available datasets, namely, EMOVO, RAVDESS, SAVEE, and Berlin Emo-DB. The best results are obtained as follows: the Chirplet + CSA + TELM combination obtains a classification accuracy of 80.63% on the EMOVO dataset, the FAWT + HHO + TELM combination obtains a classification accuracy of 85.76% on the RAVDESS dataset, the Chirplet + OIFS + TELM combination obtains a classification accuracy of 83.94% on the SAVEE dataset, and, finally, the KSTDIS + CSA + TELM combination obtains a classification accuracy of 89.77% on the Berlin Emo-DB dataset. Full article

Surface roughness and low surface energy are key elements for the artificial preparation of biomimetic superhydrophobic materials. However, the presence of micro-/nanostructures and the corresponding increase in roughness can increase light scattering, thereby reducing the surface transparency. Therefore, designing and constructing superhydrophobic surfaces that combine superhydrophobicity with high transparency has been a continuous research focus for researchers and engineers. In this study, a transparent superhydrophobic coating was constructed on glass substrates using hydrophobic fumed silica (HF-SiO₂) and waterborne polyurethane (WPU) as raw materials, combined with a simple spray-coating technique, resulting in a water contact angle (WCA) of 158.7 ± 1.5° and a sliding angle (SA) of 6.2 ± 1.8°. Characterization tests including SEM, EDS, LSCM, FTIR, and XPS revealed the presence of micron-scale protrusions and a nano-scale porous network composite structure on the surface. The presence of HF-SiO₂ not only provided a certain roughness but also effectively reduced surface energy. More importantly, the coating exhibited excellent water-repellent properties, extremely low interfacial adhesion, self-cleaning ability, and high transparency, with the light transmittance of the coated glass substrate reaching 96.1% of that of the bare glass substrate. The series of functional characteristics demonstrated by the transparent superhydrophobic HF-SiO₂@WPU coating designed and constructed in this study will play an important role in various applications such as underwater observation windows, building glass facades, automotive glass, and goggles. Full article

The skeletons of marine sponges are ancient biocomposite structures in which mineral phases are formed on 3D organic matrices. In addition to calcium- and silicate-containing biominerals, iron ions play an active role in skeleton formation in some species of bath sponges in the marine environment, which is a result of the biocorrosion of the metal structures on which these sponges settle. The interaction between iron ions and biopolymer spongin has motivated the development of selected extreme biomimetics approaches with the aim of creating new functional composites to use in environmental remediation and as adsorbents for heavy metals. In this study, for the first time, microporous 3D spongin scaffolds isolated from the cultivated marine bath sponge Hippospongia communis were used for electro-assisted deposition of iron oxides such as goethite [α-FeO(OH)] and lepidocrocite [γ-FeO(OH)]. The obtained iron oxide phases were characterized with the use of scanning electron microscopy, FTIR, and X-ray diffraction. In addition, mechanisms of electro-assisted deposition of iron oxides on the surface of spongin, as a sustainable biomaterial, are proposed and discussed. Full article

The gut microbiota performs several crucial roles in a holobiont with its host, including immune regulation, nutrient absorption, synthesis, and defense against external pathogens, significantly influencing host physiology. Disruption of the gut microbiota has been linked to various chronic conditions, including cardiovascular, kidney, liver, respiratory, and intestinal diseases. Studying how animals adapt their gut microbiota across their life course at different life stages and under the dynamics of extreme environmental conditions can provide valuable insights from the natural world into how the microbiota modulates host biology, with a view to translating these into treatments or preventative measures for human diseases. By modulating the gut microbiota, opportunities to address many complications associated with chronic diseases appear. Such a biomimetic approach holds promise for exploring new strategies in healthcare and disease management. Full article

High-resolution electronics on complex curved surfaces have wide applications in fields such as biometric health monitoring, intelligent aircraft skins, conformal displays, and biomimetics. However, current manufacturing processes can only adapt to limited curvature, posing a significant challenge for achieving high-resolution fabrication of electronics on complex curved surfaces. In this study, we propose a novel fabrication strategy that combines electric field-driven jetting and water-assisted transfer printing techniques to achieve the fabrication of high-resolution electronics on complex curved surfaces. The electric field-driven jetting enables the fabrication of high-resolution 2D electronics on sacrificial layer substrates. After dissolving the sacrificial layer, it is observed that the 2D electronics form a self-supporting structure with a certain rigidity and flexibility. During the water-assisted transfer printing process, this self-supporting structure undergoes stretching deformation with excellent conformity of the electronics to curved surfaces while effectively minimizing wrinkles. Finally, we successfully demonstrate the manufacture of 25 μm high-resolution electronics on highly curved surfaces (nautilus shell) and complex (scallop shell, stone) surfaces. The integrity of transferred circuit patterns and consistency of conductors are verified through infrared thermography analysis, confirming the feasibility of this manufacturing strategy. In addition, a protective film with strong adhesive properties is sprayed onto the transferred curved circuits to enhance their adhesion and resistance to extreme environments such as acids and alkalis. Our proposed technique provides a simple and effective new strategy for the fabrication of high-resolution electronics on complex curved surfaces. Full article

In recent years, the utilization of extremophile microorganisms for the synthesis of metal nanoparticles, featuring enhanced properties and diverse compositions, has emerged as a sustainable strategy to generate high-quality nanomaterials with unique characteristics. Our study focuses on the biosynthesis of Cu-In-S (CIS) nanoparticles, which has garnered considerable attention in the past decade due to their low toxicity and versatile applications in biomedicine and solar cells. Despite this interest, there is a notable absence of reports on biological methods for CIS nanoparticle synthesis. In this research, three yeast species were isolated from soil samples in an extreme Antarctic environment—Union Glacier, Ellsworth Mountains. Among these isolates, Filobasidium stepposum demonstrated the capability to biosynthesize CIS nanoparticles when exposed to copper sulfate, indium chloride, glutathione, and cysteine. Subsequent purification and spectroscopic characterization confirmed the presence of characteristic absorbance and fluorescence peaks for CIS nanoparticles at 500 and 650 nm, respectively. Transmission electron microscopy analysis revealed the synthesis of monodisperse nanoparticles with a size range of 3–5 nm. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles, revealing the presence of copper, indium, and sulfur. The copper/indium ratio ranged from 0.15 to 0.27, depending on the reaction time. The biosynthesized CIS nanoparticles showed higher photostability than biomimetic nanoparticles and demonstrated successful application as photosensitizers in quantum dot-sensitized solar cells (QDSSC), achieving a conversion efficiency of up to 0.0247%. In summary, this work presents a cost-effective, straightforward, and environmentally friendly method for CIS nanoparticle synthesis. Furthermore, it constitutes the first documented instance of a biological procedure for producing these nanoparticles, opening avenues for the development of environmentally sustainable solar cells. Full article