Assistance Of Electric Field Research Articles

High specific capacitance of manganese-based colloidal system with rare earth modification

Ever-increasing global energy consumption has increased aggregate demand on electrochemical energy storage devices with high energy density. Over the past few decades, manganese oxides have attracted wide attention due to their abundant reserves, low cost, environmental friendliness, and high theoretical capacity. However, most reported manganese-based materials have exhibited capacity far below the theoretical capacity, which was only on the basis of Mn3+/Mn4+ couple. The rich chemistry of manganese enables it to exist in various valence states, such as Mn0, Mn2+, Mn3+, Mn4+, and Mn7+, providing great opportunity for discovering new manganese-based electrode systems. Herein, we formed a Mn2+/Mn4+ couple from a manganese-based colloidal system with rare earth (RE) modification, which was formed in-situ on nickel (Ni) foam in KOH electrolyte under an electric field assistance. The Mn-based colloidal electrode, with Mn:Ce mass ratio of 1:0.5, achieved a high specific capacitance of 2985 F g–1 at 3 A g–1, which was higher than the theoretical capacity of 2193 F g–1 on the basis of the Mn3+/Mn4+ couple. After the addition of Ce3+, the prepared sample exhibited improved rate capability performance. Our manganese-based colloidal electrode with RE modification delivered a high specific capacitance of 1223 F g–1 at 20 A g–1, with 54.5% retention of 2243 F g–1 at 3 A g–1 at Mn:Ce mass ratio of 1:0.05. Colloidal electrode systems involving Mn-based colloids are a novel way to engineer the electrochemical performance of inorganic materials.

MOFs-derived conductive structure for high-performance removal/release of phosphate as electrode material

Porous metal-organic frameworks (MOFs) have drawn increasing attention as promising phosphate adsorbents. Yet the potential agglomeration of MOFs particles and the difficult collection process largely thwarted their application. Meanwhile, adsorbents regeneration might destroy MOFs structures due to the use of strong alkaline solution. In this work, we reported a strategy for designing and fabricating an electrode to remove phosphate based on MIL-101 derived metal/carbon via a two-step carbonization step, which not only introduced C doping but also created a stable structure. With the assistance of electric field, the migration and capture of phosphate anions were greatly enhanced. Under 1 V condition, the material exhibited a high maximum removal capacity of 97.73 mg P/g. Adsorption kinetics and parameters for phosphate at different conditions were analyzed. Langmuir and Freundlich isotherms were employed to validate the adsorption data. More importantly, the regeneration of electrode was achieved in a more facile and efficient way than micro/ nanoparticles adsorbents by simple voltage control. Such an intriguing approach may provide a new platform to further expand the use of MOFs for adsorption process.

Phase transitions and piezoelectricity enhancement around MC → O phase transition in PMN-0.34PT single crystals

Abstract Phase transitions of Pb(Mg1/3Nb2/3)O3-0.34PbTiO3 (PMN-0.34 PT) have been studied by using dielectric constant variations, polarization-electric field hysteresis loops, and polarizing light microscopy (PLM). Even without the assistance of electric field, orthorhombic (O) phase exists in the [001]C-oriented PMN-0.34 PT single crystals during the heating process, which is confirmed by the polarizer/analyzer extinction angle from full-angle in situ PLM observation combined with the grayscale image analysis. The phase transition sequence is monoclinic (MC) → O → MC → tetragonal (T) → cubic (C), which is different from the commonly accepted MC → T → C sequence. The existence of the O phase accompanies with much enhanced dielectric and piezoelectric performance, which indicates a new mechanism to produce large piezoelectricity in PMN-PT single crystals.

Electric field-assisted synthesis of Pt, carbon quantum dots-coloaded graphene hybrid for hydrogen evolution reaction

A simple method for preparation of Pt, CQDs-coloaded graphene composite for hydrogen evolution reaction (HER) is established by electrolysis-solvothermal process. Graphene is obtained by electrochemical exfoliation of graphite in cathode, while carbon quantum dots (CQDs) and Pt nanoparticles (NPs) are in-situ generated in the electrolyte simultaneously. CQDs are evolved from propylene carbonate solvent and Pt NPs are derived from reduction of Pt intermediate species generated from anodic dissolution of Pt counter electrode during electrolysis process. Then Pt NPs and CQDs are well dispersed on graphene at subsequent solvothermal process. Work voltage and electrolyte type as the key electrolysis conditions are applied to control the concentration of CQDs and Pt NPs, which decides electrochemically active surface area and HER activity of obtained catalysts. Significantly, the obtained superior catalyst with trace amount of Pt (0.145 wt%), shows markedly enhanced catalytic HER activity with mass activity of 37.5 A mg−1 at −50 mV in acidic solution, 68.2 times more active than Pt/C. This study provides a universal and promising methodology for synthesizing Pt, CQDs coloaded hybrid with the assistance of electric field as cost-effective catalysts for fuel cells.

Volume and surface memory effects on evolution of streamer dynamics along gas/solid interface in high-pressure nitrogen under long-term repetitive nanosecond pulses

Evolution of the surface streamer and the discharge mode transition from the corona discharge to the surface flashover were investigated by pulse sequence resolved electrical and optical measurements under long-term repetitive nanosecond pulses (RNP). The test sample was a cylindrical epoxy resin insulator attached with a needle electrode in 0.1–0.4 MPa nitrogen. Under positive RNP, the inception phase of subsequent streamer discharges decreases with increasing the pulse repetition frequency (PRF), and a periodical streamer stagnation phenomenon appears at high gas pressure. Under negative RNP, the surface streamer does not illustrate symbolic decreasing tendencies in light intensity and corona inception phase in gas gap. The dependence of the evolution of surface streamer velocity on PRF is correlated with the repulsive force from surface charges and the accessibility of seed electrons. Statistical characteristics of back discharges under negative RNP are qualitatively explained by the local electric field around the triple junction. The reversal phenomenon of polarity effect of the allowable repetitive working coefficient is probably resulted from the corona stabilization effect, the surface electron detrapping process, and the assistance of background electric field. Principal results qualitatively support that behaviors of surface streamer and flashover are dominated by the electric field distribution, volume and surface memory effects as well as their interactions and bidirectional transformations, which are different from the monotonically facilitative tendency predicted by the metastable-species-dominated memory effect mechanism.

Nitrification plays a key role in N2O emission in electric-field assisted aerobic composting

Nitrous oxide (N2O) emission is a serious environmental problem in composting. Previous studies have indicated that electric field assistance results in lower N2O emissions in aerobic composting; however, the exact mechanisms involved in electric-field assisted aerobic composting (EAAC) are not clear. In this study, the biological N transformation processes and the N-associated genes were investigated. The results demonstrated that electric field application inhibited nitrification, weakened the nitrifying functional genes (the hao and nxrA genes declined maximally by 86% and 86.8%, respectively), and increased the N2O consumption-related gene (nosZ) by a maximum factor of 2.76 compared with that in CAC. The correlation analysis demonstrated that nitrification was the main source of N2O emission in EAAC. The findings imply that EAAC is a promising process for mitigating N2O emission at the source during aerobic composting.

Solvothermal fabrication and construction of highly photoelectrocatalytic TiO2 NTs/Bi2MoO6 heterojunction based on titanium mesh

The fabrication of TiO2 NTs/Bi2MoO6 type-II heterojunction photocatalyst was carried out by a simple solvothermal method. Bi2MoO6 nanoparticles with nanosheet microstructures were successfully loaded on TiO2 NTs surface through the adjustment of reaction intervals. The heterojunction photocatalyst showed excellent organic dye and heavy metal ion removal performances, and nearly 100%, 75%, 100% and 100% of MO, RhB, MB and Cr (VI) were removed by simulative sunlight irradiation for 3 or 2 h, respectively. The outstanding photocatalyic performance was mainly due to the formation of type-II heterojunction between TiO2 and Bi2MoO6. The type-II heterojunction not only enhanced visible light response but also accelerated photogenerated charge carrier transfer and restrained the recombination of photogenerated electron-hole pairs with the assistance of internal electric field.

Photo-carrier extraction by triboelectricity for carrier transport layer-free photodetectors

Efficient carrier extraction is essential for high performance optoelectronic devices, such as solar cells and photodetectors. Conventional strategies to separate photogenerated carriers typically involve the fabrication of a p-n junction by doping and the use of carrier selective charge transport layers. However, these techniques often require high temperature processes or costly materials. In this work, we demonstrate an innovative and simple approach of extracting photogenerated carriers from organometallic halide perovskites utilizing triboelectricity. The triboelectric device can be easily fabricated at low temperature using inexpensive materials on plastic substrates, enabling it to be readily integrated into self-powered optoelectronic devices. As a proof-of-concept, we fabricated a triboelectrics-assisted perovskite photodetector, which enabled us to study the surface charges generated using different electrical contacts and bending conditions performed by the device. With the assistance of a triboelectric charge-induced electric field, the photocurrent and transient photoresponses were significantly enhanced. Furthermore, we integrated the plastic triboelectric device with a flexible photodetector to demonstrate this carrier collection approach in flexible/wearable electronics. To the best of our knowledge, this work is the first report of carrier extraction in organometallic halide perovskite photodetector by triboelectric charges, demonstrating a potential use for carrier extraction in other semiconductor-based optoeletronic devices.

Electric Assisted Salt-Responsive Bacterial Killing and Release of Polyzwitterionic Brushes in Low-Concentration Salt Solution.

Polyzwitterionic brushes with strong antipolyelectrolyte effects have shown great potential as versatile platforms for the development of switchable friction/lubrication and bacterial absorption/desorption surfaces. However, the surface property switches of these brushes are usually triggered by high salt concentrations (>0.53 M), thereby greatly limiting their applications in biological fields where the salt concentration for mammals is ?0.15 M. To solve this problem, an electric field was used to assist the salt-responsive process of the polyzwitterionic brushes to achieve bacterial release at low concentrations of the salt solution. Briefly, poly(3-(dimethyl (4-vinylbenzyl) ammonium) propyl sulfonate) (polyDVBAPS) brushes grafted on ITO surfaces were prepared by surface initiated atom transfer radical polymerization. The bacterial release of this surface was conducted under an electric field, where anions were migrated and enriched around the brush-grafted ITO surface as anode. The local high concentration ion led to the conformation change of the brush and release of the attached bacteria. The effect of salt type, salt concentration, electric field strength, and conducting time on the bacterial release properties were investigated. The results indicated that under an electrical field of 3 V/mm, polyDVBAPS showed release capacities of ?93% for E. coli and ?81% for S. aureus in 0.12 M NaCl electrolyte solution. Furthermore, by the introduction of a bactericidal agent, i.e., Triclosan (TCS), an antibacterial surface with dual functions of killing and release was fabricated. This surface could kill ?90% and release 95% of attached E. coli in a 0.12 M NaCl solution by the application of a 3 V/mm electric field. This work demonstrated the feasibility of triggering a salt-responsive behavior of polyzwitterionic at low salt concentration by assistance of electric field, which would greatly extend the applications of polyzwitterionic, in particular in biological applications.

Electro-activation of O2 on MnO2/graphite felt for efficient oxidation of water contaminants under room condition

The activation of oxygen (O2) under room condition is highly desirable for oxidative removal of organic pollutants in water. Herein, we report a graphite felt (GF)-supported α-MnO2 catalyst which is active for activating O2 with assistance of an anodic electric field. The electro-assisted catalytic wet air oxidation (ECWAO) process on MnO2/GF is able to rapidly degrade a variety of dyes, pharmaceutics and personal care products (PPCPs) under room condition. The congo red, basic fuchsin, neutral red and methylene blue are completely mineralized in 160 min, and the bisphenol A, triclosan and ciprofloxacin are mineralized by 89.9%, 81.5% and 65.4%, respectively, in 300 min. Mechanistic study indicates a surface-catalyzed non-free radical pathway for the oxidation of organic pollutants by O2 in the ECWAO process. The oxygen vacancies on MnO2 are identified as the catalytically active sites, at which oxygen atom is transferred from O2 to organic molecule through chemisorbed oxygen species. The anodic electric field assists such an oxygen transfer pathway by activating the complex of chemisorbed oxygen species and organic molecule through electro-oxidation reaction. The ECWAO process on MnO2/GF electrode exhibits a great potential for practical wastewater treatment under room condition.

Exploration of Flash Sintering Mechanisms and Increase Mechanical Strength of YSZ for Dental Application

Flash sintering is a rapid ceramics sintering method with an external electric field assistance. Compared to conventional sintering by which YSZ should be heated to 1200~1400OC and hold for 2~4 hours to be sintered, flash sintering can lower the sintering temperature and shorten the sintering time markedly. In addition, the grain size of YSZ observed after flash sintering is often smaller than those sintered by conventional sintering approach. However, it is still not well understood how ceramics could be sintered in a few seconds and accompanied by a sudden increase of electric conductivity of the ceramic material. One proposed explanation of the electric field effect during flash sintering is the Joule heat generation within the sample, leading to significantly higher local temperature that in turn enhances mass transfer. However, the in-situ observed temperature of flash-sintered samples in literatures suggests a diffusion rate based on Arrhenius equation insufficient to meet the required mass transfer rate for rapid densification. Flash sintering process is commonly divided into three stages. Stage I is considered an incubation time while a constant voltage is applied. Stage II is the period during which the flash event occurred, accompanied by a sharp increase of current. Stage III is the constant-current period after flash sintering when the pre-set limiting power is reached. In order to understand how electric field affects the sintering exactly, we performed flash sintering on 3YSZ compact and investigated the sample at the end of each aforementioned stages: case A, before the flash event; case B, at flash event and cut off the electric field instantly; case C, constant current mode for 300 s, as illustrated in figure (d). All of the samples are flash sintered at 850OC with an applied field of 150 V/cm and a current limit of 0.5 A. SEM images are shown in figure (a), (b), and (c), which correspond to case A, B, and C, respectively. As shown in figure (a) and (b), very little grain growth is observed under constant voltage, and then grain growth accelerated after the flash event. If we extend the holding time of constant current period, as demonstrated in figure (c), the grain boundaries merging is more obvious and larger grain sizes are observed. However, too large a grain size of YSZ could lead to phase transformation from tetragonal to monoclinic structure and in turn reduce its mechanical strength. In this work, we focus on enlarging current limit and shorten holding time to sinter YSZ of smaller grain sizes and elevate uniformity of grain distribution by improving the electric contact. The goal is to raising the hardness of sintered YSZ to 1200 HV in Vickers hardness and density to 6 g/cm3 while controlling the proportion of phase transformation to be less than 5%. We aim to flash sinter YSZ of smaller grain size and higher mechanical strength for the dental application while reducing energy consumption during its manufacture. Figure 1

Electric field endowing the conductive polyvinylidene fluoride (PVDF)-graphene oxide (GO)‑nickel (Ni) membrane with high-efficient performance for dye wastewater treatment

Due to potential toxicity of the dyes and their visibility even at the very low concentration, treatment of dye wastewater has been a matter of considerable interest. Membrane technology is an emerging technology that offers a promising way to remove dyes from wastewater. However, the membrane fouling and trade-off effect severely hinder the removal efficiency. In view of this, the conductive polyvinylidene fluoride (PVDF)-graphene oxide (GO)‑nickel (Ni) composite membrane was firstly developed and implanted into the dead-end filtration cell as the cathode in the sandwich-like electrode. Under the assistance of electric field, the conductive PVDF-GO-Ni membrane displayed 98.02% Congo red (CR) rejection with the flux of 38.39 L·m−2·h−1·bar−1, which was an encouraging result comparing to most previous reports. Moreover, PVDF-GO-Ni membrane possessed certain antibacterial ability and super anti-adhesion ability to CR molecules. The underlying mechanism of super anti-adhesion of CR molecules was investigated by quantitatively calculating the interfacial interaction energy according to the extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory. XDLVO theory indicated that the repulsive acid-based (AB) interaction energy between CR molecules and membrane surface predominantly facilitated the super anti-adhesion ability of the hydrophilic PVDF-GO-Ni membrane. The present study not only supplied a novel PVDF-GO-Ni membrane for high-efficient treatment of dye waste water, but also built an approach to quantitatively calculate interfacial interaction energy which should have a wide applications in forecasting and directing the modifications of separation membranes.

Lean methane oxidation over Co3O4/Ce0.75Zr0.25 catalysts at low-temperature: Synergetic effect of catalysis and electric field

Electric field was introduced for ultra-lean methane oxidation over a series of Co3O4/Ce0.75Zr0.25 catalysts. Catalytic activities were significantly promoted by the electric field. It was found that the catalyst with 25% of Co loading showed the highest catalytic activity at 9 mA of electric currency, and the light-off temperature (T50) was as low as 240 °C. The effect of the electric field over the catalysts was examined from the structural and surface point of view (XRD, XRS, BET, H2-TPR). The obtained results demonstrated that the electric field facilitated the release of oxygen from lattice by promoting the reduction of Ce4+ to Ce3+, therefore reinforced the formation of Co3O4 on catalyst surface. Moreover, tetrahedral Co2+ in the Co3O4 spinel were oxidized to Co3+. Besides, electric field enhanced the reducing capacity of the Co3O4 with the newly formed tetrahedral Co3+ easily reduced at low-temperature conditions. The FTIR results revealed that the active sites of methane chemisorption located respectively at tetrahedral Co3+ with active O species from lattice in the electric field, and octahedral Co3+ with pre-adsorbed gaseous O2 formed at relatively higher-temperature in conventional catalytic process. The following dehydrogenation and oxidation processes were accelerated in the electric field with fast conversion rates of intermediates, namely methyl and formates species. Based on experimental results and comprehensive analysis, the mechanism of catalytic oxidation of methane over Co3O4/Ce0.75Zr0.25 catalysts with the assistance of electric field was proposed.

Facile Construction of Defect‐rich Rhenium Disulfide/Graphite Carbon Nitride Heterojunction via Electrostatic Assembly for Fast Charge Separation and Photoactivity Enhancement

AbstractGraphite carbon nitride (CN) is one of the most researched visible light photocatalysts, but it still cannot be used practically because of its low photoactivity resulting mainly from rapid photogenerated charge recombination. To accelerate charge separation, CN was herein electrostatically assembled with ReS2, a two‐dimensional semiconductor to construct heterojunction for the first time. The electrostatic and coordination interactions between CN and defect‐rich ReS2 make them close contact to form heterojunctions. The ReS2/CN heterojunction exhibits higher photocatalytic performance in pollutant degradation owing to faster generation of reactive oxygen species than CN, as well as increased visible and near‐infrared light absorption because of strong photoabsorption of defect‐rich ReS2. The accelerated reactive oxygen species generation for the heterojunction arises from accelerated charge separation, especially fast transfer of holes from CN to ReS2 in assistance of interfacial electric field and great valance‐band edge difference. This work provides a novel CN‐based heterojunction for photoactivity improvement and illustrates significance of electrostatic attraction in fabricating heterojunctions.

Reactive Dedoping of Polymer Semiconductors To Boost Self-Powered Schottky Diode Performances.

A facile and strategic junction tuning technology is reported to boost self-powered organic Schottky photodiode (OPD) performances by synergetic contributions of reactive dedoping effects. It is shown that dedoping poly(3-hexylthiophene-2,5-diyl) (P3HT) films with 1-propylamine (PA) solution significantly reduces not only acceptor-defect density but also intrinsic doping level, leading to dramatically enlarged depletion width of metal/polymer Schottky junctions, as confirmed by ultraviolet photoelectron spectroscopy and Mott-Schottky junction analyses. As a result, whole penetration regions of photons corresponding to absorption bands of P3HT can be fully covered by the depletion region of Schottky junctions, even without the assistance of external electric fields. In addition, it is shown that non-solvent exposure effects of PA dedoping further enable lower paracrystalline disorder and, thus, higher charge carrier mobility, by means of grazing incidence X-ray diffraction, field-effect mobility, and space-charge-limited current analyses. As a result of such synergetic advantages of the PA dedoping method, non-power-driven green-selective OPDs were demonstrated with a high specific detectivity exceeding 6 × 1012 Jones and a low noise-equivalent power of 5.05 × 10-14 W Hz-0.5. Together with a fast temporal response of 26.9 μs and a wide linear dynamic range of 201 dB, the possibility of realizing non-power-driven, near-ideal optimization of solution-processed OPDs with a facile dedoping method is demonstrated.

An efficient measure to improve the NLO performance by point charge electric field

An increasing number of scientists have focused on the methods to enhance the nonlinear optics (NLO) performance of classic candidates, by chemical design/synthesis or physical measure. In order to validate an innovative strategy to enhance NLO responses while keeping the intrinsic nature of its molecular hyperpolarizabilities through the assistance of point charge electric field, we investigate the efficiency on typical D-π-A molecular hyperpolarizabilities of 4-nitroaniline a couple of point electric charge (4-nitroaniline@Na+ & Cl− in our study), together with configuration distortion and uniform external electronic field. Our work shows that the most effective method to improve its molecular hyperpolarizability is the introduction of point electric charge among the three strategies, which is ˜ around 100 times of the value using external electronic field. Moreover, in our instance the increment of its NLO response can be achieved simply by the distance of a couple of ions. Hopefully, researches with controlling of point electric charge in theory will facilitate the development of NLO materials in experiment.

Manipulation of nanostructured carbon films as field emitters in an electric-and-magnetic-field-assisted chemical vapor deposition process

To enhance the field emission performance and understand the emission essence of carbon materials, carbon films with different morphology and phase composition were fabricated by regulating the reactive gas flow ratio in a hot filament chemical vapor deposition system with the assistance of electric field and magnetic field. The characterization of carbon film quality and measurement of their field emission performance indicated that carbon nanostructures, including nanoclusters, nanopillars and nanotips, which were determined by the methane concentration in the process, were formed under the assistance of electric field. Further magnetic field assistance could lead to the formation of finer nanostructures with higher crystallinity. Field emission performance was highly dependent on the morphology and phase composition of the carbon films. Among all the samples, carbon nanotips, deposited in high methane concentration with the co-assistance of magnetic and electric field, possessed the best field emission performance, with the lowest turn-on field of 6.5 V·μm−1 (J = 10 μA·cm−2). Besides, a comparative study on the fitting degree of several conduction mechanisms revealed that the essence of field emission was the combination of several emission mechanisms, which was also dependent on the morphology and phase composition of these carbon films.

Formation of Liquid Marbles Using pH-Responsive Particles: Rolling vs Electrostatic Methods.

Aqueous dispersions of micrometer-sized, monodisperse polystyrene (PS) particles carrying pH-responsive poly[2-(diethylamino)ethyl methacrylate] (PDEA) colloidal stabilizer on their surfaces were dried under ambient conditions at pH 3.0 and 10.0. The resulting dried cake-like particulate materials were ground into powders and used as a stabilizer to fabricate liquid marbles (LMs) by rolling and electrostatic methods. The powder obtained from pH 3.0 aqueous dispersion consisted of polydisperse irregular-shaped colloidal crystal grains of densely packed colloids which had hydrophilic character. On the other hand, the powder obtained from pH 10.0 aqueous dispersion consisted of amorphous and disordered colloidal aggregate grains with random sizes and shapes, which had hydrophobic character. Reflecting the hydrophilic-hydrophobic balance of the dried PDEA-PS particle powders, stable LMs were fabricated with distilled water droplets by rolling on the powders prepared from pH 10.0, but the water droplets were adsorbed into the powders prepared from pH 3.0. In the electrostatic method, where an electric field assists transport of powders to a droplet surface, the PDEA-PS powders prepared from pH 3.0 jumped to an earthed pendant distilled water droplet to form a droplet of aqueous dispersion. Conversely the larger powder aggregates prepared from pH 10.0 did not jump due to cohesion between the hydrophobic PDEA chains on the PS particles, resulting in no LM formation.

Fabrication of Photoreactive Biocomposite Coatings via Electric Field-Assisted Assembly of Cyanobacteria.

We report how dielectrophoresis (DEP) can be used as a tool for the fabrication of biocomposite coatings of photoreactive cyanobacteria (Synechococcus PCC7002) on flexible polyester sheets (PEs). The PE substrates were precoated by a layer-by-layer assembled film of charged polyelectrolytes. In excellent agreement between experimental data and numerical simulations, the directed assembly process driven by external electric field results in the formation of 1D chains and 2D sheets by the cells. The preassembled cyanobacteria chains and arrays became deposited on the substrate and remained in place after the electric field was turned off due to the electrostatic attraction between the negatively charged cell surfaces and the positively charged polyelectrolyte-coated PE. The DEP-assisted packing of cyanobacteria is close to the maximal surface coverage of ∼70% estimated from convectively assembled monolayers. Confocal laser scanning microscopy and spectrophotometry confirm that the photosynthetic pigment integrity of the Synechococcus cells is preserved after DEP immobilization. The significant decrease of the light scattering and the enhanced transmittance of these field-assembled cyanobacteria coatings demonstrate reduced self-shading compared to suspension cultures. Thus, we achieved the assembly of structured cyanobacteria coatings that optimize cell surface coverage and preserve cell viability after immobilization. This is a step toward the development of flexible multilayered cell-based photoabsorbing biomaterials that can serve as components of "biomimetic leaves" for utilizing solar energy to recycle CO2 into fuels or chemicals.

Development of a Hybrid Piezo Natural Rubber Piezoelectricity and Piezoresistivity Sensor with Magnetic Clusters Made by Electric and Magnetic Field Assistance and Filling with Magnetic Compound Fluid.

Piezoelements used in robotics require large elasticity and extensibility to be installed in an artificial robot skin. However, the piezoelements used until recently are vulnerable to large forces because of the thin solid materials employed. To resolve this issue, we utilized a natural rubber and applied our proposed new method of aiding with magnetic and electric fields as well as filling with magnetic compound fluid (MCF) and doping. We have verified the piezoproperties of the resulting MCF rubber. The effect of the created magnetic clusters is featured in a new two types of multilayered structures of the piezoelement. By measuring the piezoelectricity response to pressure, the synergetic effects of the magnetic clusters, the doping and the electric polymerization on the piezoelectric effect were clarified. In addition, by examining the relation between the piezoelectricity and the piezoresistivity created in the MCF piezo element, we propose a hybrid piezoelement.