Original Article

A micro-sized (75 ml) MFC with graphene anode and air cathode fueled by human saliva producing higher current densities (1190 A m⁻³) than any previous air-cathode micro-sized MFCs and generated 40 times more power than that possible with a carbon cloth anode.

The p-type bismuth telluride-based polycrystalline materials suiting for low-temperature power generations (near 380 K) have been obtained through Sb-alloying and HD, which suppresses the detrimental effect of intrinsic conduction at elevated temperature via increasing the hole concentration and band gap. The hot-deformed Bi_0.3Sb_1.7Te₃ alloy, not usual composition Bi_0.5Sb_1.5Te₃, shows a maximum ZT of 1.3 at 380 K, indicating a bright application potential in low-temperature power generations.

A stretchable wrinkled organic memory has been successfully demonstrated. The stretchable organic memory with a graphene bottom electrode possesses rippled structures. The stretchable organic memory exhibits excellent electrical switching behaviors and memory effects even under repetitive stretching. It is believed that this stretchable organic memory may be beneficial for digital information storage in future stretchable electronic systems.

Flexible and transparent electronics, such as interactive digital products and human-friendly health-care monitors, are expected to fundamentally change the way of our daily life. Inorganic semiconductors, as a class of important functional materials, are key components of electronic devices. However, their applications in soft electronics are severely confined due to the brittleness. We demonstrate that by structural design of a nanobelt network, extraordinary mechanical flexibility and high optical transparency can be achieved in conventionally fragile ceramics. High-performance photodetectors based on this inorganic nanobelt network are demonstrated on multiple flexible substrates, which strongly indicates its great potential in soft electronics.

Nonpolar resistive switching reproducibly occurs in arrays of nanoscale cells composed of multilayered NiO/Pt nanowires with significantly reduced switching voltages, narrow switching voltage distributions and a robust multilevel memory effect. A high resistance ratio (∼10⁵) between the high- and low-resistance states in nanoscale cells enables stable multilevels to be induced easily by a series of pulsed voltages. The existence of intermediate resistance states in NiO/Pt nanowire arrays can be well explained by the binary-resistor model combined with energy perturbations induced by the pulse voltage. Our bottom-up approach and proposed mechanism explain the controllable multilevel memory effect.

Scanning a La-doped BiFeO₃ epitaxial thin film with a biased AFM tip, we produce straight stripe one-dimensional nanostructures in which two competing polymorphic ferroelectric phases appear alternately at the interval of ∼100 nm showing the enhancement of electronic conduction at the phase boundaries. We can create, switch and erase the eight-variant stripe nanostructures in a reversible and deterministic way by controlling the tip scanning direction and tip biased voltage. The findings provide a new pathway into one-dimensional nanostructures and versatile patterns of ferroelectric domains and interfaces.

By applying temperature gradient on the temperature-responsive wettablitity surface of block copolymer, water droplet movement by the nonmechanical origin forces is realized on the surface with high hysteresis, due to the binary collaboration effect of wettability gradient force and Marangoni force. The results help to understand the motion of droplets on the surface with high hysteresis and also provide potential application in microfluidic devices.

A simple and universal DNA-based platform is developed to implement the required two logic gates of a half adder (or a half subtractor) in parallel triggered by the same set of inputs. The developed half adder and half subtractor are operated with the same DNA platform in an enzyme-free system. The investigations provide a new way for the prototypical DNA-based arithmetic operations and also the development of advanced circuits.

In this work, transformation optics technique was applied to the thermodynamic area by using the coordinate transformation to the time-dependent heat diffusion equation, which enables the manipulation of the heat flux by predefined diffusion paths. A transient thermal cloaking device engineered with effective thermal materials was experimentally demonstrated by hiding a centimeter-sized vacuum cavity. To facilitate the fabrication a rescaled heat equation taking into account of all the pertinent parameters of various ingredient materials was proposed to guide the practical design of complex transformed thermal devices.

β-MnO₂ nanorods with exposed tunnel structures have been successfully synthesized by a hydrothermal method. The as-prepared β-MnO₂ nanorods have exposed {111} crystal planes with a high density of (1 × 1) tunnels, leading to facile Na-ion insertion and extraction. When applied as cathode materials in Na-ion batteries, the β-MnO₂ nanorods exhibited a superior electrochemical performance with a high initial Na-ion storage capacity of 350 mAh g⁻¹.β-MnO₂ nanorods also demonstrated an excellent high rate capability and a good cyclability.

High-Performance Polypyrrole Functionalized PtPd Electrocatalysts.

We demonstrate a LEGO-like assembly of free-standing film of individually operable components encapsulated in a polymer overcoat layer, leading to the integrated architecture without additional electrical connection. The free-standing components are produced by the peeling-off process. The sticky nature of polymer layer enables the construction of supercapacitor arrays and simple RLC circuits through interlocking the individual components.

Demonstration of a tunable conductivity of the LaAlO₃/SrTiO₃ interfaces by field effect drew significant attention to the development oxide-based electronics. Increase in the gate capacitance of LaAlO₃/SrTiO₃-based field-effect transistor is particularly important to the conductivity modulation and the development of logic device. Here, we demonstrate that annihilation of quantum capacitance and colossal capacitance enhancement (about 1000%) in the LaAlO₃/SrTiO₃ heterostructures by DC gate voltage at room temperature, which we attribute to the motion of oxygen vacancies through the LaAlO₃ layer thickness. The capacitor devices would provide a platform for the further development and application of metal-oxide-semiconductor transistor devices.

Soft Material Helps Cancer-Cell Capture: Soft polystyrene (PS) polymer nanotube substrate has been developed to realize rapid and highly efficient breast cancer-cell capture from whole-blood samples with high cell viability, by integrating the soft nature of PS with specific capture agents and surface structures to mimic the cell microenvironment. It is anticipated that this soft material-based substrate will provide a potentially optimal candidate for high-quality breast cancer-cell capture and detection technologies, and open a new view to design cell-material interfaces for advanced cell-based diagnostic and therapeutic platforms.

A universal process for transferring planar, transparent functional oxide thin films on to elastomeric polydimethylsiloxane (PDMS) substrates is demonstrated. This overcomes the challenge of incorporating high-temperature-processed crystalline oxide materials with low-temperature organic substrates. The process is demonstrated using indium tin oxide (ITO) thin films to realise fully transparent and flexible resistors and zinc oxide thin films. The ITO thin films on PDMS are shown to withstand uniaxial strains of 15%, enabled by microstructure tectonics. This ubiquitous process will pave the way for touch sensing and energy harvesting for displays and electronics with flexible and transparent characteristics.

Graphene quantum dots (GQDs) derived from double-walled carbon nanotubes with strong emission were prepared through solution chemistry. The introduction of GQDs in a bulk heterojunction polymer solar cell based on Poly (3-hexylthiophene):(6,6)-phenyl-C61 butyric acid methyl ester (P3HT:PCBM) resulted in the significant enhancement of power conversion efficiency (PCE). The efficiency can be further improved by adjusting the PCBM content in the active layer, with the highest PCE of 5.24%.

A novel heterojunction structure combining three kinds of semiconductors was designed and fabricated. The heterojunction structure can be used as a two-input OR gate with the combination of two diodes on the two interfaces of the organic/inorganic semiconductor. The research will have great influence in both the fundamental research field of nanoscience and the device application field of nanotechnology.

The work functions of indium tin oxide terminated with Cl and F have been studied using DFT calculations. The results show that the work function of Cl-terminated ITO is much higher than that of F-terminated ITO despite the fact that F is more electronegative than Cl. Detailed analysis through visualization of the atomic-scale charge transfer at these adatom–oxide interfaces reveals that both high electronegativity and atomic size are crucial to increase the work function of ITO.

In this article, we propose several kinds of simple nano-structures constructed by BP and SiC nanoribbons, which show peculiar electronic properties and might have promising applications in nano-electronics. SiC-BP-SiC nanoribbons are found to exhibit not only significant field-effect characteristics but also tunable negative differential resistance. ‘Y’- and ‘Δ’-shaped SiC-BP structures show significant spin polarization at their edges. Under the transverse electric field, the non-magnetic direct bandgap zigzag BP nanoribbons can change to non-magnetic indirect bandgap semiconductors, ferrimagnetic semiconductors or half-metals depending on the field strength and direction. These findings reveal the possibility of using SiC-BP nano-structures to construct multi-functional electronics.

The influence of hydrophilic additives on the underlying factors and mechanisms that govern the release of the hydrophobic drug PCTX from a blended system was investigated. The incorporation of hydrophilic PEG additives resulted in a phase-separated system with randomly distributed PCTX–PEG-rich domains in the continuous PLGA matrix. Owing to their preferential association in these domains, the enhanced release of PCTX can be controlled and modulated by varying the concentration and MW of PEG additives. The extensive porosity due to the dissolution of PCTX–PEG domains created a significant reduction in the tensile strength of these films as evaluated under constant aqueous conditions.