Magnetic Hybrid Research Articles

Adsorption of anionic dyes onto 1,5-Diphenylcarbazide functionalized magnetic hybrid polymer: Impact of water salinity and surfactants on adsorption isotherms

Herein, an effective hybrid adsorbent based on magnetic chitosan (MC) and magnetic glycidyl methacrylate (Mp(GMA)) was synthesized. The prepared hybrid material was functionalized by 1,5-Diphenylcarbazide (DPC), then employed for the adsorption of two anionic dyes (Coomassie brilliant blue G-250; CBB, and Eosin Y; EO) from their synthetic solutions. The as-fabricated adsorbent (MC-Mp(GMA)/DPC) was specifically investigated via FTIR, SEM-EDX, BET, TGA, and VSM analyses. The influence of several operational key factors; initial solution pH, initial dye concentration, contact time, temperature, and influence of cationic, anionic surfactant, and salinity on adsorption isotherms were investigated. The findings revealed that MC-Mp(GMA)/DPC highest adsorption capacities were recorded in the presence of cationic surfactant (0.795, 0.817 mmol g−1 for CBB and EO, respectively) and salinity hardly affects adsorption isotherms. Moreover, the adsorption process of each dye was reported to fit with the Langmuir model at all conditions, while the PSORE model well-defined their adsorption kinetics. Meanwhile, thermodynamics revealed that the separation of CBB and EO dyes was endothermic. Moreover, MC-Mp(GMA)/DPC possessed a desirable efficacy for the regeneration (e.g., 77.9% and 71.7 for CBB and EO, respectively) up to the 4th cycle, affirming its outstanding renewability. Overall, the produced MC-Mp(GMA)/DPC can potentially be offered as a promising recyclable dye scavenger for wastewater remediation.

Tutorial: Nonlinear magnonics

Nonlinear magnonics studies the nonlinear interaction between magnons and other physical platforms (phonon, photon, qubit, spin texture) to generate novel magnon states for information processing. In this Tutorial, we first introduce the nonlinear interactions of magnons in pure magnetic systems and hybrid magnon–phonon and magnon–photon systems. Then, we show how these nonlinear interactions can generate exotic magnonic phenomena. In the classical regime, we will cover the parametric excitation of magnons, bistability and multistability, and magnonic frequency comb. In the quantum regime, we will discuss the single-magnon state, Schrödinger cat state, and the entanglement and quantum steering among magnons, photons, and phonons. The applications of the hybrid magnonics systems in quantum transducer and sensing will also be presented. Finally, we look at the future development direction of nonlinear magnonics.

Novel and efficient electromagnetic wave absorption of SiBCN(Fe) nanofibers

In this work, novel and efficient SiBCN(Fe) nanofibers were successfully prepared by electrostatic spinning and polymer-derived ceramic (PDCs) methods, and their electromagnetic wave (EMW) absorption properties were investigated after pyrolysis at 1100–1500 °C. Notably, SiBCN(Fe) nanofibers exhibit the best EMW absorption performance after pyrolysis at 1400 °C, with a minimum reflection loss (RLmin) of −72.87 dB at 3.6 GHz and an effective absorption bandwidth (EAB, RL≤ −10 dB) of 4.34 GHz at 1.44 mm. Its excellent EMW absorption performance is attributed to its fiber structure, which facilitates the multi-level reflection and scattering of EMW. Meanwhile, the doping of Fe facilitates the in-situ generation of substances such as Fe3Si, which can impart SiBCN(Fe) nanofibers with magnetic loss and perfect impedance matching performance. The simulated radar cross-section (RCS) results show that the optimized SiBCN(Fe) nanofibers can effectively achieve the attenuation of EMW in a practical environment. Compared with many previously reported magnetic hybrid composites, SiBCN(Fe) nanofibers exhibit excellent electromagnetic absorption properties with a simpler preparation process, which have the potential to be used as lightweight, ultra-strong radar-absorbing materials.

A Fluorescent and Magnetic Hybrid Tracer for Improved Sentinel Lymphadenectomy in Prostate Cancer Patients.

In prostate cancer, sentinel lymph node dissection (sLND) offers a personalized procedure with staging ability which is at least equivalent to extended LND while inducing lower morbidity. A bimodal fluorescent-radioactive approach was introduced to improve sentinel LN (SLN) detection. We present the first in-human case series on exploring the use of a fluorescent-magnetic hybrid tracer in a radiation-free sLND procedure. Superparamagnetic iron oxide nanoparticles and indocyanine green were administered simultaneously in five prostate cancer patients scheduled for extended LND, sLND and radical prostatectomy. In situ and ex vivo fluorescence and magnetic signals were documented for each LN sample detected via a laparoscopic fluorescence imaging and magnetometer system. Fluorescence and magnetic activity could be detected in all patients. Overall, 19 lymph node spots could be detected in situ, 14 of which were fluorescently active and 18 of which were magnetically active. In two patients, no fluorescent LNs could be detected in situ. The separation of the LN samples resulted in a total number of 30 SLNs resected. Ex vivo measurements confirmed fluorescence in all but two magnetically active SLNs. One LN detected in situ with both modalities was subsequently shown to contain a metastasis. This study provides the first promising results of a bimodal, radiation-free sLND, combining the advantages of both the magnetic and fluorescence approaches.

Comparative analysis of [formula omitted] and [formula omitted] hybrid ferro-nanofluids flow under magnetic dipole effect over a slip stretching sheet

The available external manipulation of ferrofluids through magnetic fields leads to applications in magnetically controlled actuation and drug targeting. This study investigates the behavior of magnetic hybrid ferro-nanofluids flowing over a stretched sheet with the inclusion of velocity slip and a magnetic dipole. The thermal characteristic of two different hybrid ferro-nanofluids, which are ferrite-cobalt ferrite (Fe3O4/CoFe2O4) and nickel zinc ferrite-manganese zinc ferrite (NiZnFe2O4/MnZnFe2O4) dispersed into a water-ethylene glycol, are theoretically analyzed and compared. The governing equations are developed using the Tiwari and Das model. The simplified equations are solved using the Keller box method. Results show that increased ferrohydrodynamic interaction and slip velocity contribute to higher velocity profiles. A stronger magnetic field intensity, by increasing the distance of the magnetic dipole, significantly improves the velocity profile but leads to a rapid decline in the temperature field. It is found that as the dimensionless distance increases, the temperature profile drops 0.15 % from Fe3O4/CoFe2O4 to NiZnFe2O4/MnZnFe2O4. There is an immediate 0.45 % drop in the velocity profile for Fe3O4/CoFe2O4 as velocity slip enhances, compared to NiZnFe2O4/MnZnFe2O4. The thermal field rises by 1.93 % as the magnetic field distance approaches the plate, influenced by the hybrid nanoparticles' volume fraction.

Impact of vortex generator, magnetic field, and magnetic two-phase hybrid nanofluid on the performance of a dual-tube heat exchanger: Hydrodynamic and exergy analyses

In this study, a three-dimensional model of a counter-flow dual-tube heat exchanger is developed. The heat exchanger is equipped with a vortex generator, and the working fluid used is a hybrid nanofluid consisting of water and iron-copper oxide. The effects of using the hybrid nanofluid and pure water are investigated. Turbulent flow conditions are assumed within a Reynolds number (Re) range of 30,000 to 48,000, employing the realizable k-ε turbulence model. The coupled algorithm is employed to solve the velocity and pressure equations, and the equations are discretized using the least square method. The vortex generator is utilized with various pitch ratios (Ω). Furthermore, the magnetic field affects the middle section of the inner tube, with Hartmann numbers (Ha) of 35, 65, 95, and 125. The study reveals that an increase in the volume fraction (φ) positively impacts the exergy of the heat exchanger, while an enhancement in Ω negatively influences it. Furthermore, the energy efficiency improves with increasing Re. By applying the magnetic field, the maximum power of the system in producing work corresponds to Re = 36,000 because ηex is reduced when Re > 36,000. At all values of Re, the increase in Ha improves ηex.

Clinical symbiosis of hybrid nanoparticles and induced magnetic field on heat and mass transfer in multiple stenosed artery with erratic thrombosis

This article scrutinizes blood circulation through an artery having magnetized hybrid nanoparticles (silver and gold) with multiple stenoses at the outer walls and erratic thrombus of different radii at the center. In the realm of biomedical innovation, magnetized hybrid nanoparticles emerge as a captivating frontier. These nanoparticles, amalgamating diverse materials, exhibit magnetic properties that engender novel prospects for targeted drug delivery, medical imaging enhancement, and therapeutic interventions. The study was carried out employing modern bio-fluid dynamics (BFD) software. In this iterative procedure, a second-order finite difference approach is used to solve the governing equations with 0.005 tolerance. The experiment is performed on a blood conduit with mild stenosis assumptions, and expressions of temperature, resistance impedance to flow, velocity, wall shear stress, and pressure gradient are generated by employing related boundary conditions. No one has ever attempted to acquire the remedial impact of an induced magnetic field and hybrid nanoparticles on the bloodstream in a tapering artery containing multiple stenoses on the outside walls and multi-thrombus at the center using 3-D bio-fluid simulation. Furthermore, the study's findings are unique, and these computational discoveries were not previously published by any researcher. The findings suggest that hybrid nanoparticles can be used as medication carriers to reduce the impact of thrombosis and stenosis-induced resistance to blood flow or coagulation-related factors.

Electromagnetic characteristics of antisymmetric toroidal dipole array of plasmonic metasurfaces.

An antisymmetric toroidal dipole array of plasmonic metasurfaces, whose unit cell consisted of a pair of physically connected asymmetric split-ring resonators, is presented in this study. Moreover, a new paradigm was established to control toroidal electric dipole properties. Toroidal electric dipoles and electric and magnetic hybrid pseudo-anapole states are excited owing to imperfect and perfect destructive interference, respectively, which leads to the spatial separation of the electric and magnetic fields and a distinct asymmetric Fano line shape in the transmission spectrum. The imperfect destructive interference was further modified by adjusting the relative position between the even and odd layers of the metasurfaces. The scattered power of the toroidal electric dipole is tuned continuously and linearly, which enables the tailoring of the electromagnetic response. The displacement sensitivity is approximately 0.13 GHz/mm over the range 0-8 mm. The modulation depth of the scattered power of the toroidal electric dipole can reach 740%, realising a toroidal electric-dipole-to-electric-dipole transition. The proposed plasmonic metasurfaces provide a platform to efficiently control near-field enhancement, far-field radiation, and electric-magnetic separation and find potential applications in frequency-selective surfaces, sensors, filters, spectroscopic tests, and many other areas.

Development of magnetic flotation hybrid separation process for cleaner coal preparation

The magnetic flotation hybrid separation process, which combines column flotation and magnetic separation, was anticipated to beneficiate a representative coal sample acquired from the El-Maghara coal mine with a relatively high ash percentage of 27.21%. The system was designed to introduce a high gradient magnetic field to a flotation column to hinder the flotation of magnetic particles even if attached to flotation bubbles, improving the coal demineralization process and producing high quality coal. The Box-Behnken design and response surface methodology were employed to investigate and optimize the combined influence of various operating parameters on the process performance. The effects of the main operating parameters such as magnetic field strength, slurry circulation flow rate, air flow rate, collector dosage, and frother concentration were investigated. Ash percentage, combustible recovery, and separation efficiency were defined as process responses. Upgrading the coal sample under the optimum conditions of 1.2 T magnetic field strength, 1500 ml/min circulation flow rate, 11.64 ml/min air flow rate, 0.87 kg/ton diesel collector, and 42 ppm methyl isobutyl carbinol frother, the predicted and two confirmation experiments data were 7.78%, 7.89%, 7.71% ash percentages with maximum recoveries of 75.86%, 76.37%, 75.94%, and maximum separation efficiencies of 77.17%, 78.51%, 78.71% respectively.

Dual-responsive amplification strategy for ultrasensitive detection of norovirus in food samples: Combining magnetic relaxation switching and fluorescence assay

Ultra-sensitive, accurate, and specific diagnostic probes are urgently developed to overcome the limitations of conventional norovirus (NV) probes. Herein, we presented the fabrication of a dual-signal probe using multifunctionalized gold and magnetic nanoparticles hybrid composite (Fe3O4 @Au NPs) carriers for the specific detection of NV by magnetic relaxation-fluorescence bimodal sensing. The dual-specific probes were created by modifying Fe3O4 @Au NPs with antibody (Ab) and aptamer-FAM. The antigen-Ab immunoreaction caused aggregation of Fe3O4 @Au NPs, altering the magnetic relaxation signal; simultaneously, the aptamer-FAM that were originally adsorbed on the Au surface were desorbed and cleaved into the solution in the presence of NV, causing a change in the fluorescence signal. Ultrahigh detection sensitives of 0.38 and 3.45 pg/mL were obtained for the dual-modality detection platform, respectively. Furthermore, two quantitative methods obtained satisfactory spiked recoveries for NV-spiked oyster, scallop, strawberry, and tomato samples, consistent with the results of commercial ELISA kits. The results indicated that this dual-specificity assay not only was ultrasensitive but also markedly boosted analysis reliability and precision. Hence, the dual-mode biosensor exhibits high potential for NV detection in the field of food safety.

Generalized thermal properties of hybrid NANOLIQUID composed of aluminum oxide (Al2O3) and silver (Ag) nanoparticles with water (H2O) as base liquid

AbstractHeat transfer rate is numerically analyzed in convective flow of Al2O3‐Ag/ H2O hybrid nanoliquid through a stretching sheet by incorporating induced magnetic field. Results of entropy generation in system are evaluated as well. Considered physical factors associated with heat transfer are heat generation parameter and viscous dissipation. The system of nonlinear partial differential equations is modeled and dimensionally simplified by implementing boundary layer approximation assumption and proper similarity transformations. Adam's Bashforth method is applied to get highly accurate and stable numerical solutions. Numerical results of flow variables, entropy generation number and physical quantities are interpreted by way of graphs and bar charts to perceive the extensive significance of the problem. It is visualized that rise in numeric values of mixed convection parameter λ1 leads to enhance velocity; entropy generation number and Nusselt number while suppress temperature. High magnitude of heat generation parameter δ augments velocity and temperature but reverse behavior is observed for Nusselt number and entropy generation number. Moreover, the factor of viscous dissipation significantly modifies rate of flow and heat transfer under the effect of no‐slip condition on sheet. The present study is useful in different fields of industries, technological processes, mechanical processes, and electrical processes due to the applications of magnetic hybrid nanofluid with improved heat and mass transfer.

Rational design of magnetic MOFs-COFs hybrid nanozyme for the colorimetric detection of phenol

Phenol is highly toxic and can cause damage to humans and the ecosystem even at low concentrations. Therefore, developing a rapid, sensitive and easy operated detection strategy still faces challenge. In this work, the covalent organic frameworks (COFs)-reinforced peroxidase-mimicking hybrid nanozyme was rationally designed by assembly COFs on magnetic Fe3O4 @ZIF-8 nanozyme. The Fe3O4 @ZIF-8 @COF hybrid nanozyme exhibited significant improved catalytic activity and can be developed as a rapid and sensitive phenol colorimetric sensor with ease operation. The core-shell structure and the crystallinity of the as-prepared hybrid nanozyme were characterized in detail by various analytical methods SEM, TEM, FT-IR, XRD and elemental mapping. The catalytic activity of Fe3O4 @ZIF-8 @COF mimic enzyme was investigated in the presence of H2O2 using 4-aminoantipyrine (4-AAP) as the substrate. The developed Fe3O4 @ZIF-8 @COF hybrid nanozyme was applied to construct colorimetric sensor for phenol detection and the result presented high selectivity, excellent stability and good reusability with a wide linear range (6–350 μM), low detection limit (2 μM) and an advantageous response time (5 min). The designed catalyst makes the enhancement of peroxidase-like activity, which can be attributed to the unique core-shell structure with the inner catalytic site and the outer protection and enrichment COF shell. Therefore, this proposed colorimetric sensor with robust, stable and easy-recycled properties displayed excellent practical significance for the fast and sensitive detection of phenol in water environment.

Hybrid collagen–cellulose–Fe3O4@TiO2 magnetic bio-sponges derived from animal skin waste and Kenaf fibers for wastewater remediation

Water pollution from synthetic dyes and oil spills has a significant impact on the environment and living species. Here, we developed a low-cost, environmentally friendly and easily biodegradable magnetic hybrid bio-sponge nanocomposite from renewable resources such as collagen and cellulose (Kenaf fibre cellulose–collagen, KFCC). We loaded it with magnetic bimetallic Fe3O4@TiO2 (BFT) NPs to produce a photocatalyst material (KFCC-BFT) for the treatment of colored wastewater as well as a sorbent for oil–water separation. The characterization of the bimetallic BFT NPs by XRD, HRTEM and VSM showed the deposition of TiO2 particles onto the surface of Fe3O4 with lattice interlayers spacing of 0.24 and 0.33 nm for Fe3O4 and TiO2, respectively with ferromagnetic property. The UV–vis diffuse reflectance spectra result indicated that the band gap energy of bio-sponges decreases with the increase of the bimetallic moiety. The photocatalytic efficiency of the as-prepared magnetic hybrid bio-sponge in the degradation of crystal violet dye was up to 91.2% under visible light conditions and 86.6% under direct sunlight exposure. Furthermore, the magnetic hybrid bio-sponge was used to separate motor oil from water (> 99%) and had a high oil sorption capacity of 46.1 g/g. Investigation of the recyclability and reusability performance for 9 cycles revealed that the bio-sponge had a high sorption capacity for up to 5 cycles. Our results suggest that the bio-polymer-supported BFT hybrid nanocomposite is a cost-effective and easily biodegradable photocatalyst and has great potential for real-field environmental remediation applications.

Electron Spin Decoherence Dynamics in Magnetic Manganese Hybrid Organic-Inorganic Crystals: The Effect of Lattice Dimensionality.

Organic-inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead- and tin-based hybrids, these systems generally show short spin decoherence lifetimes, and their correlation with the lattice framework is still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine)2MnCl4, ((R)-3-fluoropyrrolidinium)MnCl3, and (pyrrolidinium)2MnCl4, which represent a change in lattice dimensionality from 2D and 1D to 0D, and studied their spin decoherence processes using continuous-wave electron spin resonance spectroscopy. All manganese hybrids exhibit nanosecond-scale spin decoherence time τ2 dominated by the symmetry-directed spin exchange interaction strengths of Mn2+-Mn2+ pairs, which is much longer than lead- and tin-based metal hybrids. In contrast to the similar temperature variation laws of τ2 in 2D and 0D structures, which first increase and gradually drop afterward, the 1D structure presents a monotonous rise of τ2 with the temperatures, indicating the strong correlation of spin decoherence with the lattice rigidity of the inorganic framework. This is also rationalized on the basis that the spin decoherence is governed by the competitive contributions from motional narrowing (prolonging the τ2) and electron-phonon coupling interaction (shortening the τ2), both of which are thermally activated, with the difference that the former is more pronounced in rigid crystalline lattices.

Voltage-controlled magnetic anisotropy based physical unclonable function

We design a spintronic physical unclonable function (PUF) based on sub-100 nm voltage-controlled magnetic anisotropy hybrid magnetic tunnel junctions (VCMA-MTJs). This complementary metal-oxide-semiconductor VCMA-MTJ (CMOS/VCMA-MTJ) PUF architecture was evaluated by combining micromagnetic simulations, Verilog-A modeling, and circuit-level simulations. The PUF architecture, comprising four 16 rows × 16 columns arrays, demonstrates effective read and write operations using conventional voltage sensing that are orders of magnitudes lower than previous spintronic-based PUFs. This study proves the potential of the proposed solution in security applications based on hardware authentication.

Numerical simulation optimization of a magnetic system structure for magnetic field hybrid wire-arc DED

Numerical simulation optimization of a magnetic system structure for magnetic field hybrid wire-arc DED

MHD slip effects on (50:50) hybrid nanofluid flow over a moving thin inclined needle with consequences of non-linear thermal radiation, viscous dissipation, and inclined Lorentz force

Due to their enormous implementation in engineering scrupulous, hybrid nanofluids have become a prevailing substance of consideration in mathematical and physical research. The augmentation of thermal conductivity is an exclusive emphasis of hybrid nanofluids. The fluid prototype substance probing in the existing study is the Ethylene Glycol–water (50:50) as base fluid and a mixture of nanoparticles are magnetic (Fe3O4) and non-magnetic (Al2O3) hybrid nanofluid. It is found in heat transfer and cooling in electronic devices, engines, refrigerants, energy storage and the automotive industry. To obtain solutions, the Partial Differential Equations with slip boundary conditions that describe the flow are converted into Ordinary Differential Equations with appropriate transformations using a numerically based technique known as the fourth-order Runge–Kutta method with shooting techniques. The illustration diagram of the gained outcomes accentuates the consequence of numerous physical variables on the flow dynamics in relation to fluid momentum, and thermal silhouette. Also, the consequence of heat transfer rate and surface drag force in multiple variables like Eckert number, magnetic variable, and radiation constant, are tabulated. These studies explain the decline in the thermal outline of hybrid nanofluid under slip situations when upsurges the non-linear radiation parameter. By analyzing these studies of hybrid nanofluids, it is possible to improve heat transfer efficiency and control temperature gradients in systems where nonlinear thermal radiation and viscous dissipation are important factors.

Magnetically controlled drug delivery and hyperthermia effects of core-shell Cu@Mn3O4 nanoparticles towards cancer cells in vitro

Recent increase in the integration of nanotechnology and nanosciences to the biomedical sector fetches the human wellness through the development of sustainable treatment methodologies for cancerous tumors at all stages of their initiation and progression. This involves the development of multifunctional theranostic probes that effectively support for the early cancer diagnosis, avoiding non-target cell toxicity, controlled and customized anticancer drug release etc. Therefore, to advance the field of nanotechnology-based sustainable cancer treatment, we fabricated and tested the efficacy of anticancer drug-loaded magnetic hybrid nanoparticles (NPs) towards in vitro cell culture systems. The developed conjugate of NPs was incorporated with the functions of both controlled drug delivery and heat-releasing ability using Mn3O4 (manganese oxide) magnetic core with Cu shell encapsulated within trimethyl chitosan (TMC) biopolymer. On characterization, the Cu@Mn3O4-TMC NPs were confirmed to have an approximate size of 130 nm with full agglomeration (as observed by the HRTEM) and crystal size of 92.95 ± 18.38 nm with tetragonal hausmannite phase for Mn3O4 spinel structure (XRD). Also, the UV–Vis and FTIR analysis provided the qualitative and quantitative effects of 5-fluororacil (5-Fu) anticancer drug loading (max 68 %) onto the Cu@Mn3O4-TMC NPs. The DLS analysis indicated for the occurrence of no significant changes to the particle size (around 100 nm) of Cu@Mn3O4-TMC due to the solution dispersion thereby confirming for the aqueous stability of developed NPs. In addition, the magnetization values of Cu@Mn3O4-TMC NPs were measured to be 34 emu/g and a blocking temperature of 42 K. Further tests of magnetic hyperthermia by the Cu@Mn3O4-TMC/5-Fu NPs provided that the heat-releasing capacity (% ΔT at 15 min) increases with that of increased frequency, i.e. 28 % (440 Hz) > 22.6 % (240 Hz) > 18 % (44 Hz), and the highest specific power loss (SPL) value observed to be 488 W/g for water. Moreover, the 5-Fu drug release studies indicate that the release is high at a pH of 5.2 and almost all the loaded drug is getting delivered under the influence of the external magnetic field (430 Hz) due to the influence of both Brownian-rotation and Néel relaxation heat-mediated mechanism. The pharmacokinetic drug release studies have suggested for the occurrence of more than one model, i.e. First-order, Higuchi (diffusion), and Korsemeyer–Peppas (non-Fickian), in addition to hyperthermia. Finally, the in vitro cell culture systems (MCF-7 cancer and MCF-10 non-cancer) helped to differentiate the physiological changes due to the effects of hyperthermia and 5-Fu drug individually and as a combination of both. The observed differences of cell viability losses among both cell types are measured and discussed with the expression of heat shock proteins (HSPs) by the MCF-10 cells as against the MCF-7 cancer cells. We believe that the results generated in this project can be helpful for the designing of new cancer therapeutic models with nominal adverse effects on healthy normal cells and thus paving a way for the treatment of cancer and other deadly diseases in a sustainable manner.

Interfacial modification of GO-FePt hybrid film leads to giant ultrafast optical nonlinearity

Excellent optical nonlinearity is highly promising for the development of multifunctional ultrafast photonics techniques and integrated optoelectronic devices. However, existing numerous optical materials commonly suffer from several challenges, such as bad functional integration, slow response speed, and weak optical nonlinearity thus severely hindering their extensive applications. Here, we first engineer new scalable graphene oxide (GO)-FePt films by chemistry induced self-assembly and then demonstrate the enhanced ultrafast optical nonlinearity by resorting to their interfacial modifications. It is found that the FePt magnetic nanoparticles (NPs) are easily assembled on the surface of the GO by exchanging the surface ligands of the former with evaporated solvent, leading to good water solubility and super-paramagnetism. The femtosecond Z-scan test results show that both the nonlinear saturation absorption and optical Kerr refraction of the pure GO are subjected to reversion once the FePt NPs are introduced. More importantly, we can greatly enhance the ultrafast nonlinear optics response of as-prepared GO-FePt hybrid film by promoting the concentration of magnetic NPs. In addition, the associated optical nonlinearity can be further boosted with femtosecond vectorial beams excitation instead of the linearly polarized one. In principle, the enhanced optical nonlinearity may arise from direct metal-to-semiconductor interfacial charge transfer transition (DICTT) related to the difference in work function and Fermi level together with complicated interaction between the vectorial light fields and the hybrid films. The GO-based magnetic hybrid films with giant ultrafast optical nonlinearity have potential wide-ranging applications in integrated optoelectronics, ultrafast nanophotonics, opto-magnetic storage, and beyond.

Coaxially printed magnetic mechanical electrical hybrid structures with actuation and sensing functionalities

Soft electromagnetic devices have great potential in soft robotics and biomedical applications. However, existing soft-magneto-electrical devices would have limited hybrid functions and suffer from damaging stress concentrations, delamination or material leakage. Here, we report a hybrid magnetic-mechanical-electrical (MME) core-sheath fiber to overcome these challenges. Assisted by the coaxial printing method, the MME fiber can be printed into complex 2D/3D MME structures with integrated magnetoactive and conductive properties, further enabling hybrid functions including programmable magnetization, somatosensory, and magnetic actuation along with simultaneous wireless energy transfer. To demonstrate the great potential of MME devices, precise and minimally invasive electro-ablation was performed with a flexible MME catheter with magnetic control, hybrid actuation-sensing was performed by a durable somatosensory MME gripper, and hybrid wireless energy transmission and magnetic actuation were demonstrated by an untethered soft MME robot. Our work thus provides a material design strategy for soft electromagnetic devices with unexplored hybrid functions.