Search Results (1,214)

In the current study, X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometer techniques were used to examine the impact of milling time on the microstructural and magnetic characteristics of Fe₃₀Co₂₀Ni₂₀Mn₂₀Ti₁₀ (at%) produced via mechanical alloying. Results demonstrate that phase change is dependent on up to 30 h of milling. In terms of the hcp-Fe₂Ti intermetallic and the BCC-FeCoNiMnTi supersaturated solid solution, the system maintains its two-phase structure at higher times. Additionally, the final average crystallite size was estimated to be approximately 10 nm, and the lattice strain was found to be between 0.95 and 1.15 %. As a function of milling time, the magnetic properties are discussed with the microstructural and crystallographic alterations. The collected powder after 100 h of milling has an Ms value of 28 emu/g and a Hc value of 25 Am⁻¹, which is consistent with exceptional soft magnetics. This is essentially due to the Fe₂Ti intermetallic and the BCC-Fe-based solid solution production, together with the refinement of the crystallite size. Furthermore, the presence of paramagnetic Ti atoms in solid solution and the development of high densities of defects and interfaces have been connected to the low value of Ms. Full article

Cardiac mapping is a crucial procedure for diagnosing and treating cardiac arrhythmias. Still, current clinical techniques face limitations including insufficient electrode coverage, poor conformability to complex heart chamber geometries, and high costs. This study explores the design, testing, and validation of a 64-electrode soft robotic catheter that addresses these challenges in cardiac mapping. A dual-layer flexible printed circuit board (PCB) was designed and integrated with sensors into a soft robotic sensor array (SRSA) assembly. Design considerations included flex PCB layout, routing, integration, conformity to heart chambers, sensor placement, and catheter durability. Rigorous SRSA in vitro testing evaluated the burst/leakage pressure, block force for electrode contact, mechanical integrity, and environmental resilience. For in vivo validation, a porcine model was used to demonstrate the successful deployment, conformability, and acquisition of electrograms in both the ventricles and atria. This catheter-deployable SRSA represents a meaningful step towards translating the integration of soft robotic actuators and stretchable electronics for clinical use, showcasing the unique mechanical and electrical performance that these designs enable. The high-density electrode array enabled rapid 2 s data acquisition with detailed spatial and temporal resolution, as illustrated by the clear and consistent cardiac signals recorded across all electrodes. The future of this work will lie in enabling high-density, anatomically conformable devices for detailed cardiac mapping to guide ablation therapy and other interventions. Full article

The primary aim of this study was to investigate the efficacy of tissue flossing on athletic performance measures. A secondary aim was to explore the efficacy of tissue flossing when applied to a joint or soft tissue (i.e., muscle belly) on athletic performance measures. An article search was completed in the PubMed/MEDLINE, EBSCO, SCOPUS, and OneSearch electronic databases up to May 2024. Studies were included if they used tissue flossing as a primary intervention among healthy participants and used one or more athletic performance measures as an outcome. Exclusion criteria included studies that did not investigate tissue flossing on athletic performance measures among healthy participants, studies that used tissue flossing for blood flow restriction training, case studies, narrative reviews, dissertations, conference proceedings, and papers written in a language other than English. Eighteen articles and 559 total participants were included in the final analysis. Study quality was assessed by two independent reviewers using the Downs and Black Checklist and the Oxford Centre for Evidence-based Medicine. The major findings suggest that a single tissue flossing treatment ranging from 2 to 10 min that includes active single joint or active closed chain exercises may enhance post-intervention muscle strength, jump performance, and balance up to 45 to 60 min post-intervention. Tissue flossing to a joint or soft tissue both produced mixed results among studies, a definitive answer on which technique is superior cannot be determined at this time. Further direct comparison studies are needed for these two techniques. Full article

Nowadays, self-healing materials have been studied actively in electronics, soft robotics, aerospace, and automobiles because they can prolong the life span of the materials. However, overcoming the trade-off relationship between mechanical properties and self-healing performance is challenging. Herein, graphene oxide-polyaniline (GO-PANI) filler was introduced to overcome this challenge because GO has a highly excellent modulus, and nitrogen atoms in PANI can endow a self-healing ability through hydrogen bonds. Aside from the hydrogen bond in PANI, the hydrogen bond in the carbonyl group and the disulfide exchange bond in the epoxy matrix also helped the materials heal efficiently. Therefore, the modulus of SV-GPN1 (Self-healing Vitrimer-GO-PANI1) reached 770 MPa, and a 65.0% healing efficiency was demonstrated. The modulus and self-healing efficiency were enhanced after adding GO-PANI filler. The self-healing ability, however, deteriorated when adding more GO-PANI filler because it hindered the collision between the molecules. Meanwhile, SV-GPN1 was excellent in reproducibility, which was proven by the experiment that 16.50 mm thick SV-GPN1 also displayed a self-healing ability. Thus, SV-GPN1 can be applied to structural materials in industries like aerospace because of its self-healing ability, excellent modulus, and reproducibility. Full article

This study investigates the stability, electronic structure, and optical properties of the GaN/g-C₃N₄ heterojunction using the plane wave super-soft pseudopotential method based on first principles. Additionally, an external electric field is employed to modulate the band structure and optical properties of GaN/g-C₃N₄. The computational results demonstrate that this heterojunction possesses a direct band gap and is classified as type II heterojunction, where the intrinsic electric field formed at the interface effectively suppresses carrier recombination. When the external electric field intensity (E) falls below −0.1 V/Å and includes −0.1 V/Å, or exceeds 0.2 V/Å, the heterojunction undergoes a transition from a type II structure to the superior Z-scheme, leading to a significant enhancement in the rate of separation of photogenerated carriers and an augmentation in its redox capability. Furthermore, the introduction of a positive electric field induces a redshift in the absorption spectrum, effectively broadening the light absorption range of the heterojunction. The aforementioned findings demonstrate that the optical properties of GaN/g-C₃N₄ can be precisely tuned by applying an external electric field, thereby facilitating its highly efficient utilization in the field of photocatalysis. Full article

This work evaluated bacterial cellulose (BC) as a possible biodegradable soft electronics substrate in comparison to polyethylene terephthalate (PET), while also focusing on evaluating hybrid MXene/BC material as potential flexible electronic sensor. Material characterization studies revealed that the BC material structure consists of nanofibers with diameters ranging from 70 to 140 nm, stacked layer-by-layer. BC samples produced are sensitive to post-treatment with isopropanol resulting in a change of structural and mechanical properties. The viscoelastic properties of the BC substrates have been studied experimentally in comparison with the PET film. Aged BC substrate showcased similar viscoelastic properties stability, while exhibiting better properties above 70 °C, with total storage modulus change of −15% and loss modulus change of 21%. MXenes prepared using the Minimally Intensive Layer Delamination (MILD) method were screen-printed onto BC substrates and PET films to form MXene/BC (MX/BC) and MXene/PET (MX/PET) devices. The electrical properties results showcased different resistive behavior on both BC and PET substrate samples with different impedance moduli. MX/PET presented lower sheet resistance of around 156 Ω·sq⁻¹, while MX/BC was 2733 Ω·sq⁻¹. Finally, the MX/BC and MX/PET devices were subjected to repeatable quasi-static load tests and the piezoresistive sensing behavior of the devices has been reported. Full article

In contemporary times, a significant portion of the population experiences symptoms of temporomandibular joint (TMJ) dysfunction. The objective of this study was to evaluate the effects of a single-session TMJ soft tissue therapy on the TMJ and cervical spine mobility as well as on body balance and the foot load distribution. This study was a parallel-group, randomized, controlled trial with a 1:1 allocation ratio. Fifty women aged 20–30 years diagnosed with myofascial pain in the TMJ area were included in the study and divided into two groups. The experimental group received TMJ soft tissue therapy. The following research tools were used: a Hogetex electronic caliper, a CROM Deluxe, and a FreeMed Base pedobarographic platform. In the experimental group, an increase in mobility within all assessed jaw and cervical spine movements was observed. This change was statistically significant (p < 0.05) for lateral movement to the left, abduction, and protrusion of the jaw (an increase of 10.32%, 7.07%, and 20.92%, respectively) and for extension, lateral bending to the right and left, and rotation to the right and left, of the cervical spine (an increase of 7.05%, 7.89%, 10.44%, 4.65%, and 6.55%, respectively). In the control group, no significant differences were observed. No significant changes were observed in the load distribution and body balance assessment. A single session of TMJ soft tissue therapy increases jaw and cervical spine mobility but does not impact body balance or foot load distribution in static conditions in women diagnosed with myofascial pain in the TMJ area. Full article

A flexible pressure sensor, capable of effectively detecting forces exerted on soft or deformable surfaces, has demonstrated broad application in diverse fields, including human motion tracking, health monitoring, electronic skin, and artificial intelligence systems. However, the design of convenient sensors with high sensitivity and excellent stability is still a great challenge. Herein, we present a multi-scale 3D graphene pressure sensor composed of two types of 3D graphene foam. The sensor exhibits a high sensitivity of 0.42 kPa⁻¹ within the low-pressure range of 0–390 Pa and 0.012 kPa⁻¹ within the higher-pressure range of 0.4 to 42 kPa, a rapid response time of 62 ms, and exceptional repeatability and stability exceeding 10,000 cycles. These characteristics empower the sensor to realize the sensation of a drop of water, the speed of airflow, and human movements. Full article

Angle-resolved photoelectron spectrometers with microchannel plate detectors and fast digitizer electronics are versatile and powerful devices for providing non-invasive single-shot photon diagnostics at a MHz repetition rate X-ray free-electron lasers. In this contribution, we demonstrate and characterize the performance of our two operational photoelectron spectrometers for the application of hard X-rays and soft X-rays as well as new automation tools and online data analysis that enable continuous support for machine operators and instrument scientists. Customized software has been developed for the real-time monitoring of photon beam polarization and spectral distribution both in single-color and two-color operation. Hard X-ray operation imposes specific design challenges due to poor photoionization cross-sections and very high photoelectron velocities. Furthermore, recent advancements in machine learning enable resolution enhancement by training the photoelectron spectrometer together with an invasive high-resolution spectrometer, which generates a response function model. Full article

Water-in-oil microemulsions, as stable colloidal dispersions from quasi-ternary mixtures, have been used in diverse applications, including nanoreactors for confined chemical processes. Their use as soft templates not only includes nanomaterial synthesis but also the interfacial assembly of nanoparticles in hybrid nanostructures. Especially the hierarchical arrangement of different types of nanoparticles over a surface in filament networks constitutes an interesting bottom-up strategy for facile and tunable film coating. Herein, we demonstrate the versatility of this surface assembly from microemulsion dispersions. Transmission and Scanning Electron Microscopy, in addition to UV–Vis Transmittance Spectroscopy, proved the assembly tunability after solvent evaporation under different conditions: the nanostructured films can be formed over different surfaces, using different compositions of liquid phases, as well as with the incorporation of different nanoparticle materials while keeping equivalent surface functionalization. This offers the possibility of adapting different components and conditions for coating tuning on a larger scale with simple procedures. Full article

Heterostructured materials consist of heterogeneous zones with dramatic variations in mechanical properties, and have attracted extensive attention due to their superior performance. Various heterostructured materials have been widely investigated in recent years. In the present study, a combination of two different types of heterogeneous structures, a surface bimodal structure and gradient structure, was designed using the traditional surface mechanical attrition treatment (SMAT) method in pure copper, and the mechanical properties and microstructural evolution of dual-heterostructure Cu were studied in depth. In total, 100 stainless steel balls with a diameter of 6 mm were utilized to impact the specimen surface at room temperature for a short period of time. In this work, the sample surface was divided into hard areas and soft areas, along with a roughly 90 μm gradient structure in the cross-sectional direction after 30 s of SMAT processing. After the partial SMAT processing, lasting 30 s, the strength increased to 158.0 MPa and a considerable ductility of 25.7% was sustained, which overcomes the strength–ductility trade-off. The loading–unloading–reloading (LUR) test was utilized to measure the HDI stress, and the result showed that the HDI stress of the partial SMAT sample was much higher than the annealed one, especially for the Cu-SMAT-30S specimen, the strength of which increased from 80.4 MPa to 153.8 MPa during the tensile test. An in situ digital image correlation (DIC) investigation demonstrated that the strain developed stably in the Cu-SMAT-10S specimen. Furthermore, electron backscatter diffraction (EBSD) was carried out to study the microstructural evolution after partial SMAT processing; the KAM value increased to 0.34 for the Cu-SMAT-10S specimen. This research provides insights for the effective combination of superior strength and good ductility in dual-heterostructure materials. Full article

Tissue regeneration relies on the mechanical properties of the surrounding environment, and it has already been shown that mechanostimulation is highly dependent on the stiffness of the native biological tissue. The main advantage of injectable hydrogels in medical applications is their ability to be delivered through minimally invasive techniques. Natural polymer-based hydrogels have been widely used in biomedical applications, due to their high biocompatibility, low immunogenicity, and similarity to soft tissues. However, the crucial combination of low stiffness with high resilience has not been achieved for natural polymers. The current study focuses on the development of novel gelatin-based injectable hydrogels for soft tissue regeneration applications, elucidating the effects of the formulation parameters on the resilience, microstructure, biocompatibility, and mechanical properties. Non-foamed hydrogels demonstrated resilience of at least 95%, while porous hydrogels maintained resilience above 90%, allowing them to withstand mechanical stresses and dynamic conditions within the body. The adjustable modulus of these hydrogels provides the necessary flexibility to mimic the mechanical properties of soft and very soft tissues, without compromising resilience. Environmental Scanning Electron Microscopy (ESEM) observations of the porous hydrogels indicated round interconnected pore structures, desired for cell migration and nutrient flow. Biocompatibility tests on fibroblasts and pre-adipocytes confirmed high biocompatibility, both directly and indirectly. In summary, structuring these new hydrogels for achieving adjustable stiffness, along with the excellent resilience and biocompatibility, is expected to enable this new technology to fit various soft tissue regeneration applications. Full article

In recent years, the field of micro- and nanochannel fabrication has seen significant advancements driven by the need for precision in biomedical, environmental, and industrial applications. This review provides a comprehensive analysis of emerging fabrication technologies, including photolithography, soft lithography, 3D printing, electron-beam lithography (EBL), wet/dry etching, injection molding, focused ion beam (FIB) milling, laser micromachining, and micro-milling. Each of these methods offers unique advantages in terms of scalability, precision, and cost-effectiveness, enabling the creation of highly customized micro- and nanochannel structures. Challenges related to scalability, resolution, and the high cost of traditional techniques are addressed through innovations such as deep reactive ion etching (DRIE) and multipass micro-milling. This paper also explores the application potential of these technologies in areas such as lab-on-a-chip devices, biomedical diagnostics, and energy-efficient cooling systems. With continued research and technological refinement, these methods are poised to significantly impact the future of microfluidic and nanofluidic systems. Full article

This study explores the application of AncorLam HR (Höganäs, Sweden), a soft magnetic composite material, in the stator core of an axial flux permanent magnet drive motor. Building on previous research that provided mechanical and thermal properties of the material, the focus is on analyzing how the manufacturing process affects the motor core’s shape. A bulk prototype was created based on case 3, which demonstrated the least deviation in density and internal stress. The prototypes were produced under the conditions of SPM 7 and 90 °C, and a heat treatment in a nitrogen atmosphere for 1 h, resulting in an average density error of 0.54%, confirming process effectiveness. A microstructural analysis using scanning electron microscopy (SEM) on Sample 2, with the highest density, confirmed consistency between simulation and prototype trends. Electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) analyses revealed that the internal phase structure remained unchanged. Energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) identified the elimination of phosphorus (P) during molding, affecting the insulating layer, a critical factor for SMC materials. In motor simulations and actual measurements, the average torque was recorded as 37.7 N·m and 34.7 N·m at 1500 rpm and 27.7 N·m and 25.1 N·m at 2000 rpm, respectively. The torque comparison observed in the actual measurements compared to the simulation results indicates that the output loss increases in the actual measurements due to the deterioration of the insulation performance judged based on the microstructure evaluation. This study confirms the viability of using AncorLam HR in motor cores for electric vehicles and provides key data for improving the performance. Full article

Reducing the saturation magnetostriction is an effective way to improve the performance of soft magnetic materials and reduce core losses in present and future applications. The magnetostrictive properties of binary Fe-based alloys are investigated for a broad variety of alloying elements. Although several studies on the influence of Cu-alloying on the magnetic properties of Fe are reported, few studies have focused on the effect on its magnetostrictive behavior. High pressure torsion deformation is a promising fabrication route to produce metastable, single-phase Fe-Cu alloys. In this study, the influence of Cu-content and the chosen deformation parameters on the microstructural and phase evolution in the Fe-Cu system is investigated by scanning electron microscopy and synchrotron X-ray diffraction. Magnetic properties and magnetostrictive behavior are measured as well. While a reduction in the saturation magnetostriction λ_s is present for all Cu-contents, two trends are noticeable. λ_s decreases linearly with decreasing Fe-content in Fe-Cu nanocomposites, which is accompanied by an increasing coercivity. In contrast, both the saturation magnetostriction as well as the coercivity strongly decrease in metastable, single-phase Fe-Cu alloys after HPT-deformation. Full article