Articles

Selective growth of ZnO nanorods/reduced graphene oxide composites via IR laser-induced reaction is developed for electrochemical devices. Optimized design of interdigitated supercapacitor electrodes can be achieved by programming of laser scanning lines. The integration of ZnO NRs on rGO improves supercapacitor performances due to synergistic effects of pseudo capacitance (ZnO) and electric double layer capacitance (graphene).

An effect of atomic-scale surface modulation on the magnetic properties and the interfacial Dzyaloshinskii-Moriya interaction (IDMI) is shown in Pt/CoFeSiB/X(MgO, Ta, Ru) ultrathin films sputtered on the epitaxial Pd layers of the different thickness and surface morphology. The correlated roughness of the bottom and top interfaces of CoFeSiB increases IDMI values by up to 2.5 times, with the maximum magnitude D_eff = −0.88 erg/cm². The main reasons for this significant enhancement are the intermixing at interfaces and the correlated interface-roughness variations, which both affect electronic transport across the interface and, as a result, the degree of the electron scattering.

To achieve growth factor-free angiogenesis, a lipopolysaccharide-mimicking dodecyl group-modified gelatin microparticle (C12-MP) was fabricated. The water suspension of C12-MP formed a syringe-injectable hydrogel with shear-thinning properties. The C12-MP hydrogel induced localized and sustained angiogenesis in vivo for 22 days by stimulation of toll-like receptor 4 accompanied by endogenous growth factor secretion.

In this work, we report a strategy to build programmable atom equivalents (PAEs) with tailorable DNA bond length and bond energy using DNA encoders carrying consecutive adenines (polyA). We find that the bond length and bond energy can be tuned by programming the topologic configurations of the DNA encoders, which lead to differently leveled bonds and asymmetric PAEs allowing for directional, hierarchical assembly of multi-particle structures. This programmable bonding system may provide a new route for building complex plasmonic superstructures.

We report methacrylated silk fibroin sealant (Sil-MAS) with rapid crosslinkable, highly adhesive and biocompatible properties and demonstrate its versatility as medical glue. The excellence for physical properties of Sil-MAS is revealed via in vitro mechanical tests and ex vivo aorta pressure test. In in vivo biological tests on skin, liver, and blood vessels of rat, Sil-MAS showed a superb hemostatic and adhesive ability with high biocompatibility. Specifically, Sil-MAS strongly contributed to fast wound healing. Furthermore, we showed that Sil-MAS could be an ideal photocuring laparoscopic medical glue in laceration rabbit model of liver and stomach serosa using self-made endoscopic device.

A sequentially formed hybrid hydrogel system consisting of collagen and alginate was designed to control cell shape in 3D. The cell with different spreading state had significantly different responses to mechanical (i.e., matrix stiffness) and biochemical (i.e., transforming growth factor-β1 (TGF-β1)) cues.

Electric-field-driven ion migration is an effective way to control many physical properties such as electric and magnetic properties of materials. In this research, we demonstrated that remarkably small electric field as low as 10⁵ V/m can effectively modulate resistance of a GdO_x microwire due to the lateral motion of oxygen ions. This result enables mimicking a synaptic device with low power consumption like as a brain. Furthermore, huge MR modulation of the GdO_x microwire with the electric field provides novel functionality as an electromagnetic device.

We show an efficient spin injection technique for a semiconductor using an atomically controlled ferromagnet/ferromagnet/semiconductor heterostructure with low-resistive Schottky-tunnel barriers. Even for semiconductor spintronic devices, the symmetry matching of electronic bands between the ferromagnet and the semiconductor should be considered. This approach provides a new solution for the simultaneous achievement of highly efficient spin injection and low electric power at the electrodes in semiconductor devices at room temperature.

Since the interfacial effect has been commonly understood to be generated entirely at the boundary between the two atomic layers, the strength of the interfacial effect has been considered independent of the thickness of each layer. In this study, contrary to the common concept, we show that the interfacial phenomenon requires threshold thickness for full emergence and is suppressed when it is too thin, by providing the result of the peculiar ferromagnet layer thickness dependence of the Dzyaloshinskii-Moriya interaction (DMI). Our result refines conventional perspectives on interfacial phenomena and provides the optimum thickness to maximize DMI for technological applications.

Very efficient, fast and scalable Fluidized Bed Reactor Atomic Layer Deposition (FBR-ALD) of highly dense and uniform Pt nanoparticles (NPs) on the functionalized carbon were successfully demonstrated for the proton exchange membrane fuel cell (PEMFC) application. The textural properties, functional groups and structural defects of the carbon supports significantly influenced Pt NPs deposition. A proper carbon supporter matching for FBR-ALD of Pt resulted in excellent electrochemical properties, long-term durability and fuel cell performance.

A germole-containing π-conjugated polymer is prepared from the corresponding tellurophene-containing polymer by its Te–Li exchange reaction using n-butyllithium followed by the reaction with dimethylgermanium dichloride. The low-lying LUMO energy level of the germole-containing π-conjugated polymer is also described.

The fiber membrane prepared from silk fibroin was modified by polydopamine and grafted the liposomes encapsulated leptin that endow the fiber with vascularization. The fiber membrane was covered with the defect of oral mucosa in rabbits, and leptin was released from the broken liposomes to promote early vascularization and accelerate the regeneration of mucous membrane.

The structure of a high-temperature non-glass forming liquid Er₂O₃ was investigated by a combination of density measurements in the International Space Station and synchrotron X-ray diffraction measurements utilizing levitation techniques with the aid of computational and advanced mathematical analyses. These multidisciplinary approaches revealed that unusually sharp diffraction peak in the liquid is originated from the formation of distorted tetraclusters whose homology is similar to that of the crystalline phase.

Using a combination of angle-dependent spectroscopic ellipsometry and angle-resolved photoemission spectroscopy as a function of temperature and supported by first-principles calculations, we reveal a new pair of correlated plasmonic excitations at 1.04 and 1.52 eV and a significant Fermi level shift of 0.12 eV, accompanied by spectral weight transfer in the topological insulator, Bismuth Selenide (Bi₂Se₃). Interestingly, such a spectral weight transfer over a broad energy range causes a drastic change in the charge-carrier density whereby the contribution of charge-carriers in the bulk starts to rival those in the surface states and Bi₂Se₃ becomes more uniformly conducting.

An electrically tunable photonic band gap structure of monodomain blue phases shows the wide tunable band gap range of ~241 nm. A novel chiral monomer enables us to stabilize the blue phases and to induce electrostriction upon biased electric fields. This device also exhibits a color gamut 85% of NTSC with high color purity owing to narrow bandwidth of 31 nm.

Non-destructive ultrafast control of magnetic vortices by a simple sequence of time asymmetric electric-field pulses.

Magnetic refrigeration, which is based on the magnetocaloric effect (MCE), is an emerging pathway for environment-friendly refrigeration. In this work, we performed a machine learning based approach to discover experimentally that HoB₂ exhibits |ΔS_M| = 40.1 J/kg K (0.35 J/cm⁻³ K) for μ₀ΔΗ = 5 Τ at second order transition of T_C ~ 15 K, having the largest |ΔS_M| around this temperature region. Thus, HoB₂ is a highly suitable material for hydrogen liquefaction and low-temperature magnetic cooling applications. Our study also sheds light on the machine learning approach as an effective method for searching functional materials characterized by complex physical properties.

Precise control of colloidal-semiconductor-quantum-dots (CQD) assembly morphologies and the related carrier transport characteristics are vital to advance their utilisations. Each application requires different assembly types to exploit either the quantum confinement effect or the large surface-to-volume ratio. On-demand control of CQD-solids‘ morphology are demonstrated using variety of assembly methods. Employment of the electric-double-layer gating on varieties of CQD solids reveals their intrinsic carrier transport and accumulation characteristics. Compact superlattice structure shows high conductivity, and the hierarchical porous assembly exhibits high carrier accumulations. These flexibilities in assembly controls and characteristic tunings signify CQD versatilities as building blocks for different modern electronics.

A low toxicity and high efficiency nucleic acid delivery system is the key to the successful implementation of gene therapy. In this study, a novel fluorinated polycationic carrier was used to effectively inhibit tumor growth by targeting VEGF genes with RNAi technology based on its unique fluorine effect, providing a feasible strategy for future clinical solid tumor treatment.

A submicron structure strategy was introduced in a selective laser melted (SLM) Ag-Cu-Ge alloy, showing semi-coherent precipitates distributed in a discontinuous but periodic fashion along the cellular boundaries. It leads to a remarkable strength of ~410 MPa with ~16% ductility, well surpassing the strength-ductility combination of their cast counterparts. The hierarchal SLM microstructure and high density of internal defects leading to a high strain hardening rate and strong strengthening. Premature failure occurred due to the external defects, such as pores and unmelted particles. This work paves a way for additively manufacturing materials towards high strength–ductility synergy.