Articles in 2019

The adhesive lipo-hydrogel (A-LIP-PEG) fabricated by mixing PEG hydrogels and adhesive liposomes can be locally injected into the osteoporotic fracture and bone marrow cavity, where A-LIP-PEG can release adhesive liposomes based on the principle of electrostatic attraction to adhere to the bone injury area to promote bone reconstruction.

In this work, the quantum Griffiths singularity (QGS) of superconductor-insulator transition (SIT) is discovered in TiO thin films with insulating normal states. A magnetic field-tuned SIT with a diverging dynamic critical exponent, the direct evidence of QGS, is observed in TiO thin films with different thicknesses. The critical magnetic field H_c tends to saturate at low temperature, different from the upturn trend of H_c in superconductor-metal transition (SMT) systems. The results extend the QGS scenario from SMT systems to SIT systems, and provide decisive clues to conclude that the QGS is a common feature of crystalline superconducting thin films.

A dielectric elastomer actuator (DEA) which can provide reconfigurable 3D shape morphing was reported in this work. The reconfigurable actuator was fabricated by integrating the DEA with the ethyl cellulose (EC) paper. The mechanical actuation from the DEA under electrical bias was “instructed” by the origami EC paper to achieve designed shape changes. The crease patterns in the EC paper can be reprogrammed on demand, delivering alternative shape changes in the reconfigurable actuator. The strategy developed in this paper provides a promising approach to create sophisticated 3D shapes from DEAs without the requirement of complicated and bulky device architectures.

The Mo₂N-CoO hollow heterostructures are designed synthesis by the nitridation of a hollow Co-Mo-O precursor from controllable reaction of ZIF-67 (Co source and template) with Na₂MoO₄ (Mo source and OH- source). The catalyst exhibits good HER performance with an overpotential of 65 mV at 10 mA cm⁻² benefited from the combined virtues of hollow structure and heterojunction. The adjudication of MOFs makes current route promising toward the design of the transition metal-based catalyst for catalytic application.

Organic molecular crystals (OMCs) are shown to be an ideal material for organic photosynaptic devices, which provide homophylic memory and transinformation functions of neurons by means of a unique photon-induced charge transfer effect. As a result, a proof-of-concept artificial image-perception system is demonstrated by integrating the OMC-based photosynapses on a flexible substrate.

An efficient and resource-free pre-enrichment method using epigallocatechin gallate (EGCG), a polyphenolic biomolecule, has been developed, which enables to isolate and detect exosomal miRNA in human blood plasma samples. The system comprises three steps: (1) EGCG-mediated exosome aggregation, (2) filter-based exosome isolation, and (3) molecular beacon-based detection of target exosomal miRNA. Using blood samples from cancer patients, including those with gastric cancer and hepatocellular carcinoma, our EGCG-assisted miRNA diagnostic system can detect levels of target miRNAs (miR-21, -27a, and -375) in exosomes correlated well with those in an open-geodatabase. Our study highlights the use of a bio-adhesive-mediated preparation method in clinical samples, which can effectively achieve sample isolation and enrichment for exosome-based molecular diagnostics.

Surface electromyography (sEMG) is widely used to analyze human movements, including athletic performance. Here, we develop a skin-contact patch consisting of kirigami-based stretchable wirings and conductive polymer nanosheet-based ultraconformable bioelectrodes that can detect sEMG signals from the palm muscle during baseball pitching. We observe differences in the activity of the palm muscle between different types of pitches—fastball and curveball. This sEMG measurement system will enable the analysis of motion in unexplored muscle areas, leading to a deeper understanding of muscular activity during performance in a wide range of sports and other movements.

The periodic domain pattern of BiFeO₃ enables the anisotropic superconductivity in YBa₂Cu₃O_7 − x. In this work, we introduce a design of periodic multiferroic domain patterns to create the anisotropic superconductivity. High T_C can be found when we measured the resistance parallel to the domain wall direction and the broader transition with lower T_C is found to be perpendicular to the domain walls. (a) and (b) the resistance versus temperature in YBa₂Cu₃O_7 − x/BiFeO₃ heterostructures with two different domain patterns 109° and 71°, respectively.

(a) Schematic illustration of volume (v) - Pressure (P) - Temperature (T) diagram of the metallic glass. The process of creating ultra-dense glassy state through the high-pressure heat treatment is described (A → B → C → D → E). (b) New type of ultra-dense anomalous metallic glass was confirmed to be created by density and electric resistivity measurements.

Highly correlated pair arrangement of mixed alkali ions for the origin of the mixed alkali effect.

Three-dimensional nanocup Bi_3.25La_0.75Ti₃O₁₂–CoFe₂O₄ heterostructure film is obtained via a heavily Co, Fe co-doped ferroelectric Bi_3.25La_0.75Ti₃O₁₂ target during pulsed laser deposition. The unique 3D nanocup architecture beyond usual architectures enables reversible magnetoelectric switching of the multiferroic heterostructure film through overcoming leakage issues, as well as efficient interfacial strain coupling based on their structural benefits.

Inspired by the design philosophy of classical rebar steel-reinforced concrete in building industry, continuous Ti alloy reinforced aluminum matrix composites (AMCs) were architected for the first time by an original micro-casting process in this study. The yield strengths of present AMC samples reach 400~660 MPa, which are much higher than all the commercial or laboratorial cast Al-Si alloys (55~310 MPa). With the help of 3D printing technology, the present method makes it possible to “architect” the AMC like building a house, and reinforce the matrix at the designed position.

We reveal unusual electronic and structural changes of nano-crystalline CsPbBr₃ at different temperatures. Using high-resolution spectroscopic ellipsometry, high-resolution transmission electron microscopy, terahertz spectroscopy and supported by first-principles calculations, we find that a new dual structural phase is observed due to an effect of the material’s nano-crystalline nature. We also develop a method of determining the phase transitions within the material through the identification of optical transitions within the electronic structure and the comparison of experimental data and theoretical models. Our result shows the importance of the interplay between charge and lattice in determining structural and electronic properties of nano-crystalline materials.

Inspired by the rolling mechanism of the proboscis of a butterfly, a rollable electronics which can be rolled and unrolled on demand is developed. The rollable platform provides sufficient force which grips onto the entire target surface without destroying the target. Micro bio-objects are gripped by using the rollable platform and their tiny motions are successfully detected with the sensor on the platform. Furthermore, detecting pulse wave signals of the swine is successfully conducted by rolling up the rollable system around the blood vessel of swine, which result proves the feasibility of rollable platform as a biomedical device.

The dual-adhesive and bioactive hydrogel ‍is designed and prepared for wound closure and wound healing by incorporation of bioglass into oxidized sodium alginate (OSA) hydrogel system, in which the multifunctional ions released from bioglass play a key role for the dual-adhessiveness to both tissues and implantable materials and bioactivity in enhancing angiogenesis during wound healing.

By developing a controlled synthesis approach, the PB@PCN nanohybrid with optimal thickness is obtained for tumor treatment and imaging. The core and shell of this multifunctional nanohybrid cooperate to achieve combined photothermal/photodynamic therapy of tumor. The PB@PCN nanohybrid is further camouflaged by tumor cell membrane to endow good immune evasion and active targeting ability.

Dielectric elastomer actuators (DEAs) often suffer from time-dependent deformations due to their inherent viscoelastic properties. Herein, the viscoelastic effects were tuned through copolymerization between a polar crosslinker and a polyurethane acrylate DEA. With polar groups present in the crosslinker, the dielectric constant was effectively increased, achieving higher area strains compared to that exhibited by low viscoelastic elastomers such as silicone. Furthermore, improved dynamic response actuation performances were achieved with 90% of its maximum actuation obtained in less than 1 s while viscoelastic drifts were reduced to a negligible amount. These findings provide a facile approach to achieve rapid and stable DEAs.

A bioinspired monstera leaf-like superwettable film with porous g-C₃N₄ nanosheets as ion-accessible channels has been developed, which shows favorable electrochemical kinetic behavior in ionic liquid electrolyte. As a proof-of-concept application, high performance flexible ionogel-based supercapacitors (FISCs) have been elaborately fabricated, which can be charged by harvesting renewable energy sources and effectively power to various portable electronics.

A new quasi 1D compound Ba₃TiTe₅ was synthesized at high pressure and high temperature, which has been evidenced to be a well-defined 1D conductor. Here, for Ba₃TiTe₅, in-situ high-pressure techniques were employed to study the emerging physics dependent on interchain hopping, such as the Umklapp scattering effect, SDW/CDW, superconductivity and non-Fermi Liquid behavior. The pressure induced superconductivity was observed. It is suggested that the appearance of superconductivity is associated with the fluctuation due to the suppression of Umklapp gap and the enhancement of T_c is related with the fluctuation of the SDW/CDW.

Synchrotron-based Bragg coherent x-ray diffraction (CXD) measurements proposed to study giant magnetorestriction in nickel NW: (a) Monochromatic X-ray beam is focused by Kirkpatrick-Baez mirrors, which creates a localized illumination on the sample (S). By rotating the sample through the Bragg condition in increments of about 0.005 degrees, CXD patterns in the vicinity of the (111) and (002) reciprocal lattice points are recorded with a two-dimensional pixelated detector. A series of diffraction patterns (collected as a function of external magnetic field H) are shown here. The interference fringes are due to the finite extent of the nanowire. The color scale is calibrated in units of X-ray photons per pixel; the center of the pattern reaches a value of 9,000, but is saturated here. (b) SQUID-hysteresis loops of a 200 nm wide and 2 micron long nickel nanowire measured with an applied field at room temperature. (c) Relative change in the lattice spacing (corresponding to the asymmetry and shift of the center of mass of the measured Bragg peaks) along the < 100 > direction and the < 110 > directions. Measurements are taken during a cyclic loading (increasing magnetic field strength) and unloading procedure.