Dental implants rely on a stable and functional interface between the implant surface, surrounding tissues, and the oral microbial environment. While titanium remains the clinical gold standard due to its mechanical properties and capacity for osseointegration, peri-implant inflammation and biofilm-associated infection continue to compromise long-term outcomes. Consequently, there is growing interest in multifunctional implant surfaces capable of simultaneously regulating microbial colonisation, immune responses and peri-implant tissue integration. Advances in surface engineering and biomaterials science have revealed that implant surface chemistry and micro- and nanoscale topography strongly influence protein adsorption, immune activation, cellular behaviour, and bacterial attachment at the host-implant interface. Inspired by naturally antimicrobial and self-cleaning biological surfaces, biomimetic approaches have led to the development of mechano-bactericidal nanostructured titanium interfaces capable of physically inactivating bacteria while maintaining cytocompatibility and enhancing osteogenesis. This review examines the mechanobiological principles governing host-implant interactions and examines current strategies for engineering multifunctional antimicrobial, immunomodulatory, and regenerative implant surfaces. The translational challenges limiting clinical implementation, including mechanical durability, biological masking of engineered surfaces and long-term functional stability, are also discussed, together with emerging interest in alternative implant materials such as zirconia. Collectively, biomimetic multifunctional implant surfaces represent a promising strategy for improving long-term implant integration and peri-implant tissue health, although further translational and clinical validation remains necessary before widespread clinical adoption.

The harsh lunar environment presents unique challenges, particularly the pervasive lunar dust, which poses significant risks to both equipment and human operations. This review comprehensively examines the latest advancements in passive lunar dust mitigation surfaces, focusing on preparation, processing methods, analysis techniques, properties, and applications. We explore various materials and surface engineering strategies developed to counteract the abrasive and adhesive nature of lunar dust. Detailed insights into the preparation and characterization of these surfaces, including their mechanical and tribological properties, are provided. Additionally, we discuss state-of-the-art processing techniques such as coating, texturing, and self-cleaning mechanisms, highlighting their efficacy in mitigating dust accumulation. Advanced analytical methods employed to assess surface performance under simulated lunar conditions are reviewed. The potential applications of these technologies span from lunar habitats and rovers to spacesuits and solar panels, emphasizing their critical role in ensuring the success of lunar missions. Passive lunar dust mitigating coatings could be used in combination with active methods such as electrostatic dust removal, mechanical brushing, and magnetic systems to reduce the power requirements, or in applications in which active methods of mitigation are not feasible. Finally, we delve into future directions and cutting-edge approaches, including the integration of nanotechnology and smart materials, to enhance the durability and functionality of dust mitigation surfaces. This review aims to provide a comprehensive understanding of passive lunar dust mitigation, guiding future research and development in this pivotal area of space exploration.

Developing multifunctional nanomaterials with independently reactive surface groups is promising for advanced catalytic, environmental, and sensing technologies. Here, we present a versatile strategy to engineer bifunctional magnetic nanoparticles integrating both thiol and amine surface chemistries on a single particle. A TiO2 shell was deposited on Fe3O4 nanoparticles, pre-immobilized on a Si wafer, via atomic layer deposition (ALD) to create titania-modified magnetic nanoparticles. Sequential silanization was performed with (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES) which introduced thiol (–SH) and amino (–NH2) groups, respectively. Surface characterization using X-ray photoelectron spectroscopy (XPS) confirmed the successful incorporation of both moieties while the nanoparticles maintained high magnetization as confirmed by magnetometry measurements. Results demonstrate that the ALD-assisted sequential modification enables controlled stepwise surface functionalization without compromising magnetic properties. The resulting material is presented as a proof-of-concept bifunctional magnetic platform for future conjugation and application-specific studies, including immobilization of biomolecule (e.g., antibodies and nucleic acids), targeted adsorption, and multicomponent catalysis.

ABSTRACT With the prevalence of biomaterial‐related infections and the rapid emergence of antibiotic‐resistant strains of bacteria, the need for functional biomaterial coatings that have antibacterial properties has drastically increased over the past few decades. Recently, there has been interest in coatings of group IV transition metals such as hafnium (Hf) and zirconium due to their resistance to corrosion and inherent hardness. Here we fabricate nanostructured Hf surfaces via physical vapor deposition through a colloidal template made from either silica (Si) or polystyrene (PS) particles. The physical properties of the Hf structures were characterized by atomic force microscopy (AFM), while chemical characterization was carried out using water contact angles (WCAs) and X‐ray photoelectron spectroscopy (XPS). We show that the properties of the final Hf structures are heavily influenced by the composition and size of the colloid used as the template layer. The use of inorganic Si‐based colloidal templates resulted in an inverse structure with relatively low Hf content (0.9–7.9 Atom%), whereas polymeric PS‐based templates resulted in a multilayer system comprised of the PS‐template layer underneath the deposited Hf layer, resulting in a much higher Hf content (8.6–22.3 Atom %). Moreover, antibacterial analysis against Gram‐positive Staphylococcus aureus revealed that surfaces produced using the 0.093 µm PS template (PS0.093) provided an 87% killing efficiency along with a 98.6% reduction in adherent cells compared to flat control surfaces. On the contrary, the antibacterial tests again Gram‐negative Escherichia coli showed significant killing efficiency and antiadhesive behavior across a range of nanostructures. The results demonstrate that the nanoscale surface properties of structured Hf coatings play a role in the ability of Hf to be antibacterial, with potential to be used on medical implants.

Advancements in nanotechnology have positioned coatings as a pivotal field with the potential to significantly impact both industry and society. This review delves into nanomaterials and their potential to create smart coatings capable of real-time monitoring and flexible electronics applications. The mechanisms of conductivity and sensing capabilities within these coatings are emphasized to highlight their importance in the context of artificial intelligence. Furthermore, the current trends shaping the coatings industry are summarized, such as the concept of electronic skin (E-skin) and increasing focus on sustainability. In the digital era, the integration of the Internet of Things (IoT) is set to transform the future of coatings, enhancing their intelligence and environmental interactivity. Smart coatings are poised to revolutionize our interaction with the environment, spanning applications from consumer goods to robotics and sensors. The ongoing development of these materials and technologies promises to unlock new and exciting possibilities. By discussing the above aspects in detail, this review positions itself as a forward-looking contribution that summarizes the state-of-the-art and anticipates future directions for smart coatings, offering insights into how ongoing advancements can unlock new possibilities for both industrial applications and societal impact.

The removal of heavy metal ions, such as lead (Pb2+), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb2+ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe2O3) phase. IONPs were characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). A novel electrochemical method was developed for the silanization of IONPs using tetraethoxysilane (TEOS), (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES). The resulting silane-modified IONPs were evaluated for the magnetic removal of Pb2+ ions, with TEOS-modified IONPs demonstrating superior performance. This material exhibited a high adsorption capacity of 519 mg/g at a Pb2+ ion concentration of 300 ppm, and high removal efficiency across a range of Pb2+ ion concentrations, attributed to its Fe2O3@SiO2 core-shell structure. This study highlights the potential of the electrochemical synthesis and silanization of nanoparticles for heavy metal remediation in water.

Traditionally, polymer coatings have relied on volatile organic solvents that pose significant health hazards and contribute to environmental pollution. In response, waterborne polymer formulations have emerged as a more sustainable alternative, offering reduced emissions and improved safety. However, despite these environmental advantages, waterborne systems often fall short of matching the mechanical performance of their solvent-based counterparts. This study investigates the influence of graphene oxide (GO)/waterborne polyurethane (WPU) and graphene paste (G)/WPU dispersions as novel sizing agents on the mechanical performance of glass fibre-reinforced polymer composites. Dispersions containing 0.1, 1, and 5 wt% of G and GO in WPU were prepared, cast into films, and subjected to tensile testing. The optimal formulations-WPUGO0.1 and WPUG0.1-demonstrated superior properties, with maximum tensile strengths of 7.2 MPa and 17.4 MPa, respectively. To evaluate their applicability, desized glass fibres (GFs) were dip-coated with these formulations and integrated into epoxy composites. Morphological analysis revealed that WPUG0.1-coated GFs exhibited the smoothest surfaces, while WPUGO0.1-coated GFs displayed mixed smooth and textured features, suggesting improved interfacial adhesion. Immersion DMA at 76 degrees C and 88% relative humidity revealed that EP-WPUGO0.1 composites exhibited the lowest moisture uptake and the highest storage modulus (14,650 MPa)-a 28.3% increase over neat epoxy and a 20.5% improvement over WPUG0.1. These mechanical and environmental enhancements were supported by chemical characterization and surface morphology, establishing a robust Material-Process-Microstructure-Performance (MP2) relationship. Overall, the findings highlight the potential of graphene-based nanofillers to reinforce WPU coatings, enabling the development of high-performance, environmentally resilient composites for advanced structural applications.

Inverse opal (IO) structures based on photonic colloidal crystal (PCC) templates are types of materials that possess unique optical properties due to their ordered arrays. These materials have the ability to manipulate the propagation of light, producing unique reflection spectra and structural colours. Due to these properties, IOs have been used as optical sensors for various applications such as the detection of physical, chemical, and biological entities. This review begins with a brief introduction of PCCs, IOs and their preparation procedures. The recent advancements in the applications of IOs for sensing temperature, pH, humidity, chemical compounds (such as organic solvents and heavy metal ions), and biological entities (such as tumour cells, viruses and bacteria) are then discussed in detail. The review also explores strategies and techniques aimed at enhancing the sensitivity and lowering the limit of detection of IO-based sensors. Finally, it addresses the current challenges, existing limitations, and prospective future directions in the development and deployment of IO-based sensors.

Stemness of mouse embryonic stem cells (mESCs) can be maintained in vitro using biophysical factors including surface topography. More specifically, multidirectional symmetries have shown promise in limiting cell-substrate interactions, yielding better stemness maintenance. Here, a parylene-C coating was deposited onto binary colloidal crystals (BCCs) to generate imprinted substrates with concave bowl-like micro/nanotopographies possessing multidirectional symmetry. Remarkably, the parylene coating is shown to have the fidelity to imprint sub-2 μm structures. The mESC response to these topographies observed in culture demonstrates the complementary influence of microtopography and nanotopography. While the nanoroughness associated with the small particle imprints appears to govern the attachment of cells, the microroughness associated with large particle imprints is able to limit the interaction of cells with the substrate thereby confining spreading. Our results demonstrate that imprinted BCCs with the combination of 5 μm (large) and 110 nm (small) particle imprints are able to provide spatially limited attachment of cells, resulting in improved colony shape, enhanced growth rate and upregulation of the expression of stemness markers of mESCs in culture in the presence of LIF. Our results are expected to contribute to the development of novel cell culture substrates for use in the efficient expansion of stem cells for tissue engineering and regenerative medicine applications.

Despite their widespread utilization in biomedical applications, these synthetic materials can be susceptible to microbial contamination, potentially compromising their functionality and increasing the risk of infection in patients. In this study, molybdenum (Mo), an essential metal in biological systems, was investigated as a Mo-based cold-sprayed coating on poly(dimethylsiloxane) (PDMS) for its potential use as biocompatible and antimicrobial surfaces for biomedical applications. Various cold-spray parameters were employed in the fabrication of Mo-embedded PDMS surfaces to alter the surface structure of the substrate, Mo loading density, and embedding layer thickness. Specifically, relatively low nozzle scanning speeds were used to develop high-density Mo-embedded PDMS surfaces. A comprehensive analysis was conducted to investigate how cold-spray processing parameters affect the surface topography, wettability, and chemical properties. The ability of the Mo-embedded PDMS to inhibit the colonization of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa bacterial species was demonstrated by both live/dead staining and disk diffusion methods. Surfaces with higher Mo loading densities significantly reduced the level of bacterial attachment and enhanced the bactericidal activity upon contact. Also, the level of Mo ion release over a 14-day period was measured and correlated to the properties of the substrate surface. Furthermore, attachment, viability, and proliferation of osteoblast-like MG63 cells were assessed to investigate the effect of Mo ion release on the biocompatibility of fabricated coatings. A notable decrease in cell viability and delayed growth of MG63 cells became evident after 7 days of incubation with the highly Mo-loaded samples. While this study enhanced our understanding regarding the engineering of composite materials for combatting microbial infections, the findings also suggest that the release of Mo ions may detrimentally affect osteoblast survival, potentially compromising the long-term functionality of orthopedic implants produced using this technique.

As a member of transition metal dichalcogenides (TMDCs), molybdenum disulfide (MoS2) gains considerable attention from the research community for its potential in hydrogen gas sensing applications due to its layered structure which has a higher surface area and excellent gas adsorption ability. Pristine MoS2-based gas sensors exhibit low sensitivity and a slow, often incomplete recovery process, which adversely affects their overall performance. Therefore, various strategies are employed to enhance the performance of the sensors, including decorating MoS2 with noble metals, fabricating nanocomposites with semiconductor metal oxides (SMOs), and integrating other functional materials like graphene and reduced graphene oxide (rGO). This review article provides an overview of chemiresistive MoS2 based gas sensors and systematically examines MoS2-based hydrogen sensors, including pristine MoS2, noble metals decorated MoS2, and MoS2 functionalized with SMOs and other materials. Additionally, the review discusses the effects of different morphologies, comparing sensor properties, mechanisms, and highlights key findings. Finally, the challenges, limitations and future direction for MoS2 based sensor for hydrogen detection are discussed.

The formation of pathogenic biofilms on medical devices is a major public health concern accounting for over 65% of healthcare-associated infections and causing high infection morbidity, mortality, and a great burden to patients and the healthcare system due to its resistance to treatment. In this study, we developed a chitosan-based antimicrobial coating with embedded mesoporous silica nanoparticles (MSNs) to load and deliver eugenol, an essential oil component, to inhibit the biofilm formation of common bacteria in medical-device-related infections. The eugenol-loaded MSNs were dispersed in a chitosan solution, which was then cross-linked with glutaraldehyde and drop-casted to obtain coatings. The MSNs and coatings were characterized by dynamic light scattering, Brunauer-Emmett-Teller analysis, attenuated-total-reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, 3D optical profilometry, and scanning electron microscopy. The release behavior of eugenol-loaded MSNs and coatings and the antibiofilm and antimicrobial activity of the coatings against adherent Staphylococcus aureus, methicillin-resistant S. aureus, and Pseudomonas aeruginosa were investigated. Eugenol was released from the MSNs and coatings in aqueous conditions in a controlled manner with an initial low release, followed by a peak release, a decrease, and a plateau. While the chitosan coatings alone or with unloaded MSNs demonstrated limited antimicrobial effects and still supported biofilm formation after 24 h, the coating containing eugenol not only reduced biofilm formation but also killed the majority of the attached bacteria. It also showed biocompatibility in indirect contact with NIH/3T3 fibroblasts and a high percentage of live cells in direct contact. However, further investigations into cell proliferation in direct contact are recommended. The findings indicated that the chitosan-based coating with eugenol-loaded MSNs could be developed into an effective strategy to inhibit biofilm formation on medical devices.

Robotic additive manufacturing using a cold spray deposition head attached to a robotic arm can deposit material in a solid state with deposition rates in kilogrammes per hour. Under such a high deposition rate, the complicated interplay between the robot’s motion, gun standoff distance, spray angle, overlapping, and the interaction of supersonic powder particles with a growing structure could cause overabundance or deficiency of material build-up. Over time, the accumulation of these discrepancies can negatively affect the overall shape and size of the final manufactured object. In-process spatio-temporal 3D reconstruction, also known as 4D reconstruction, could allow for early detection of deviations from the design, thus providing the opportunity to rectify at an early stage, making the process more robust, efficient and productive. However, in-process model reconstruction is challenging due to the dynamic nature of the scene (e.g. sensor and object relative movements), the three-dimensional growth of a time-varying build object, the textureless nature of build surfaces, and its computational complexity. We propose a real-time, in-process 4D reconstruction framework for free-form additive manufacturing processes, such as cold spray that deals with a real-time dynamic and evolving scene built by incremental deposition of materials. In our approach, temporal point clouds from three cameras are acquired and segmented to extract the region of interest (build object). The subsequent multi-temporal and multi-camera registration of the segmented 3D data is addressed by combining geometrically constrained Fiducial marker tracking and plane-based registration without drift accumulation. Finally, the registered point clouds are fused via voxel fusion of growing parts to reconstruct the 3D model of the object with smoothened surfaces. The proposed solution is deployed and verified in a robotic cold spray cell with different test scenarios and shape complexities.

The wound management field faces significant challenges due to antimicrobial resistance (AMR) and the complexity of chronic wound care. Effective wound treatment requires antimicrobial dressings to prevent bacterial infections. However, the rise of AMR necessitates new antimicrobial agents for wound dressings, particularly for addressing bacterial pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Endophytic fungi, known for producing diverse bioactive compounds, represent a promising source of such new agents. This study tested thirty-two endophytic fungi from thirteen distinct Australian native plants for their antibacterial activity against S. aureus. Ethyl acetate (EtOAc) extracts from fungal culture filtrates exhibited inhibitory effects against both methicillin-sensitive S. aureus ATCC 25923 (MIC = 78.1 µg/mL) and MRSA M180920 (MIC = 78.1 µg/mL). DNA sequence analysis was employed for fungal identification. The most active sample, EL 19 (Chaetomium globosum), was selected for further analysis, revealing that its EtOAc extracts reduced S. aureus ATCC 25923 biofilm formation by 55% and cell viability by 57% to 68% at 12 × MIC. Furthermore, cytotoxicity studies using the brine shrimp lethality test demonstrated low cytotoxicity up to 6 × MIC (25% mortality rate) with an LC50 value of 639.1 µg/mL. Finally, the most active sample was incorporated into polycaprolactone (PCL) fiber mats via electrospinning, with resultant inhibition of S. aureus species. This research underscores the potential of endophytic fungi from Australian plants as sources of substances effective against common wound pathogens. Further exploration of the responsible compounds and their mechanisms could facilitate the development of wound dressings effective against MRSA and innovative biofilm-resistant electrospun fibers, contributing to the global efforts to combat AMR.

Among different materials that have been used for hydrogen sensing, one-dimensional (1D) nanostructures have shown promising results due to their enhanced specific surface area, nanoporosity and improved surface characteristics (in particular, uniformity and stability) facilitate high number of active sites. This paper aims to comprehensively review 1D nanostructure-based hydrogen sensors from three different aspects including: (1) Synthesis techniques: briefly overview the four primary synthesis techniques and how the critical processing parameters affect the morphology and sensing behavior, (2) Materials: properly distinguish the sensing mechanisms and properties of inorganic materials such as metal oxide semiconductors (MOS) combined/doped with organic carbon-based materials and polymers, and how the heterostructures can improve the sensing performance, and (3) Enhancement schemes such as additive functionalisation, material composition and light-assisted approaches to further elevate sensing characteristics. Future challenges are yet to be investigated in this area, which is discussed in this review to enlighten the way for future explorations.

Cold spray additive manufacturing is an emerging solid-state deposition process that enables large-scale components to be manufactured at high-production rates. Control over geometry is important for reducing the development and growth of defects during the 3D build process and improving the final dimensional accuracy and quality of components. To this end, a machine learning approach has recently gained interest in modeling additively manufactured geometry; however, such a data-driven modeling framework lacks the explicit consideration of a depositing surface and domain knowledge in cold spray additive manufacturing. Therefore, this study presents surface-aware data-driven modeling of an overlapping-track profile using a Gaussian Process Regression model. The proposed Gaussian Process modeling framework explicitly incorporated two relevant geometric features (i.e., surface type and polar length from the nozzle exit to the surface) and a widely adopted Gaussian superposing model as prior domain knowledge in the form of an explicit mean function. It was shown that the proposed model could provide better predictive performance than the Gaussian superposing model alone and the purely data-driven Gaussian Process model, providing consistent overlapping-track profile predictions at all overlapping ratios. By combining accurate prediction of track geometry with toolpath planning, it is anticipated that improved geometric control and product quality can be achieved in cold spray additive manufacturing.

In this study, a wound dressing of electrospun polycaprolactone (PCL) fibers incorporating the antimicrobial peptide (AMP) nisin was fabricated. Nisin was physically adsorbed to the PCL fibers and tested for antibacterial activity against both Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). The PCL fibers had an average diameter of 1.16 μm ± 0.42 μm and no significant change in diameter occurred after nisin adsorption. X-ray photoelectron spectroscopy (XPS) analysis of the fibers detected nitrogen indicative of adsorbed nisin and the signal was used to quantify the levels of coverage on the fiber surfaces. In vitro nisin release studies showed a burst release profile with 80 % of the nisin being released from the fibers within 30 min. Air plasma pre-treatment of the PCL fibers to render them hydrophilic improved nisin loading and release. Antibacterial testing was performed using minimum inhibitory concentration (MIC) and surface attachment assays. The released nisin remained active against both Gram positive S. aureus and Gram negative P. aeruginosa, which has previously been difficult to achieve with single polymer fiber systems. Mammalian cell culture of the nisin coated fibers with L-929 mouse fibroblasts and human epidermal keratinocytes (HEKa) showed that the nisin did not have a significant effect on the biocompatibility of the PCL fibers. The results presented here demonstrate that the physical adsorption, which is a post-treatment, overcomes the potential limitations of harsh chemicals and fabrication conditions of electrospinning from organic solvents and provides a drug loading system having effective antibacterial properties in wound dressings.

Toolpath planning is an essential component of robotic additive manufacturing. An efficient toolpath strategy allows parts to be made that are geometrically accurate, free of defects, have good mechanical properties and have low residual stress. Toolpaths for cold spray additive manufacturing have some technical constraints that need to be considered compared to their counterpart designed for conventional 3D printing machines. This study presents an automated toolpath planning method based on offset contours. The generated toolpath is globally continuous, layer-wise setting, making it suitable for robotic cold spray additive manufacturing. The toolpath algorithm was tested on a variety of geometries to demonstrate its robustness. One model was selected for printing using a commercial high-pressure cold spray system. The experimental results show that our method is applicable to cold spray robotic additive manufacturing for near-net shape construction. The method is particularly good for web-rib structures.

Cold spray additive manufacturing (CSAM) can produce particle-reinforced metal matrix composites (MMCs) by accelerating metal/metal or metal/ceramic particle combinations towards a substrate surface. The harder reinforcement particles become embedded into the softer metallic matrix. The secondary material may also help reduce the deposit's porosity depending on the particles' relative hardness and density. In this research, four material combinations were investigated by adding one of the following secondary materials at 10 wt% to commercial-purity (CP -Grade 2) titanium powder; (i) yttria-stabilised zirconia -(Y2O3)0.08(ZrO2)0.92, (ii) tita-nium carbide - TiC, (iii) titanium diboride - TiB2, and (iv) tungsten - W. The mechanical properties of samples following vacuum heat treatment are compared and related to the microstructural interactions between the two materials during annealing. These results show that cold spraying a hard secondary material at 10 wt% with titanium has a reinforcing effect, increasing the material's tensile strength; however, its ductility decreases slightly. The strengthening and ductility loss effect was particularly notable for the Ti blends with W and TiC.