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All-carbon memristive synapse is built through photo-reduction of a nanocomposite comprised of graphene oxide and N-doped carbon quantum dots. The analog-type resistive switching was demonstrated, which enabled the emulation of synaptic learning and pattern recognition with high accuracy. The all-carbon devices possess excellent transferability, flexibility and resistance to high temperature, showing the potential for the development of wearable neuromorphic computing system.
A liquid-based neuromorphic device that can mimic the movement of ions in a nervous system is demonstrated by controlling Na+ movement in an aqueous solution. The liquid-based neuromorphic device consists of disodium terephthalate, Nafion, NaCl solution, and electrodes. The top and bottom electrodes work as pre- and post synaptic neurons, respectively, and the NaCl solution/Na2TP@Nafion works as a synapse. The device shows short-term and long-term plasticity such as EPSC, PPF, STDP, potentiation, and depression.
Water of aqueous PEDOT:PSS solution was successfully exchanged with ethylene glycol or ethanol solvents using ultrafiltration method. This novel solvent exchange process enables uniform and conformal nano-coating of PEDOT:PSS on hydrophobic substrates without the addition of surfactants. This process can be widely used in fabrication of various sensors or electronic devices using conducting polymers.
4D Printing Conduits: Electromagnitized carbon porous nanoccookies (NCs) under MF facilitate magneto-electrical conversion for growth factor release and cell simulation. Integrating four-dimensional (4D) printed technology, exposed NCs are able to enhances the cell adhesion and manifest directly electromagnetic stimulation to cells.
It is still a mystery whether disorders could be beneficial for the superconductivity or not. In this work, it is surprising to find out that the carbon disordered 2D β-Mo2C crystal sheet shows a much stronger superconductivity than the carbon ordered 2D α-Mo2C crystal sheet, and the in-situ order-disorder transition from α-Mo2C to β-Mo2C induced by e-beam irradiation results in an enhanced superconductivity. Especially, the Tc variation trends of α-Mo2C and β-Mo2C are different under hydrostatic pressures. These results highlight the important role of disorders in the superconducting properties owing to the carbon distributions in Mo2C.
Understanding the correlation between atomic-scale structural/elastic fluctuations and local plastic rearrangements (shear transformation zone (STZ)) is essential to the widespread use of metallic glasses (MGs). We report a strategy to control the local stress state and enhance the shear stability of MGs. The enhanced degree of structural/elastic heterogeneities relates to the increased nonaffine thermal strain of the short- and medium-range order. We demonstrate that variations in the stress field around STZ affect their dynamics and percolation process, the progressive formation of shear bands, and, consequently, the macroscopic deformability of MGs. This work paves a new way for designing ductile MGs.
Quantum dot LED (light-emitting diode) optimization through the control of charge carriers’ kinetics is presented using impedance spectroscopy. The mobility of charge carriers through each one of the layers provide a path to estimate the transition time of each one of the charge carriers toward the emitting layer. By focusing on thickness optimization of electron transferring layer we can control the transition time of charge carriers and maximize radiative recombination.
Our findings unearth the great importance of the size, core structure, and surface ligands in dictating the antibacterial activity of silver nanoclusters (AgNCs). Owing to the presence of amphiphilic ligands, AgNCs are more prone to adsorb the membrane and following endocytosis towards targeted bacterial cells, associated with membrane damage, as reflected by reinforced release of malondialdehyde (MDA). AgNCs bear strong peroxidase-like activity, coupled to massive production of reactive oxygen species (ROS). Altogether, these outstanding features of AgNCs resultantly elevated the bacteria-killing efficacy through impairing cell wall/membrane, promoting oxidative stress and attenuating pivotal cellular processes, e.g., ATP synthesis.
Speed-programmed melt electrospinning writing (sMEW) is used to create a hierarchically ordered biomimetic scaffold with long-range patterned and short-range porous architectures for cell growth in patterns with tunable cell density.
A sunlight management strategy in perovskite solar cells (PSCs) using silicon quantum dots (SiQDs) is proposed. Due to the reabsorption of visible light induced by SiQDs, the external quantum efficiency spectra of PSCs in a wide wavelength range of 360–760 nm is significantly improved, resulting in facilitated photocurrent collection and enhanced performance of SiQD-based PSCs.
Tailored hardening behavior of monolithic bulk metallic glass (BMG) is demonstrated experimentally. A 2D gradient rejuvenation is introduced into ZrCuAl BMG by a novel heat treatment method. The gradual change of free volume realizes sustainable hardening until fracture. The local free volume related to the rejuvenation state controls the shear band angle and the maximum effective shear stress. Hence, shear band propagation is prohibited and the formation of a complete shear plane transecting the whole specimen is blocked. The current approach offers a new paradigm for utilizing hardening capability of BMG as practical engineering materials.
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 Deff = −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 GdOx 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 GdOx 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.
