Wafer-Scale Microwire Transistor Array Fabricated via Evaporative Assembly

One-dimensional (1D) nano/microwires have attracted significant attention as promising building blocks for various electronic and optical device applications. The integration of these elements into functional device networks with controlled alignment and density presents a significant challenge for practical device applications. Here, we demonstrated the fabrication of wafer-scale microwire field-effect transistor (FET) arrays based on well-aligned inorganic semiconductor microwires (indium-gallium-zinc-oxide (IGZO)) and organic polymeric insulator microwires fabricated via a simple and large-area evaporative assembly technique. This microwire fabrication method offers a facile approach to precisely manipulating the channel dimensions of the FETs. The resulting solution-processed monolithic IGZO microwire FETs exhibited a maximum electron mobility of 1.02 cm² V^–1 s^–1 and an on/off current ratio of 1 × 10⁶. The appropriate choice of the polymeric microwires used to define the channel lengths enabled fine control over the threshold voltages of the devices, which were employed to fabricate high-performance depletion-load inverters. Low-voltage-operated microwire FETs were successfully fabricated on a plastic substrate using a high-capacitance ion gel gate dielectric. The microwire fabrication technique involving evaporative assembly provided a facile, effective, and reliable method for preparing flexible large-area electronics

Metallic Grid Electrode Fabricated via Flow Coating for High-Performance Flexible Piezoelectric Nanogenerators

Transparent conducting electrodes (TCEs) based on metallic grid structures have been extensively explored for use in flexible and transparent electronics according to their excellent conductivity and flexibility. Previous fabrication methods have been limited by the complexity and expense of their processes. Here, we have introduced a simple and cost-effective flow-coating method for preparing flexible and transparent metallic grid electrodes using silver nanoparticles (AgNPs). The process comprises only two steps, including patterning and sintering the horizontal AgNPs lines, followed by patterning and sintering the longitudinal AgNPs lines. The grid width could be easily controlled by varying the concentration of the AgNP solution and the grid spacing could be controlled by varying the distance moved by a translation stage between intermittent stops. The optimized Ag grid electrode exhibited an optical transmittance at 550 nm of 86% and a sheet resistance of 174 Ω/sq. The resulting Ag grid electrodes were successfully used to prepare a flexible piezoelectric nanogenerator. This device showed good performance, including an output voltage of 5 V and an output current density of 0.5 μA/cm²

Gate- and Light-Tunable pn Heterojunction Microwire Arrays Fabricated via Evaporative Assembly

One-dimensional (1D) nano/microwires have attracted considerable attention as versatile building blocks for use in diverse electronic, optoelectronic, and magnetic device applications. The large-area assembly of nano/microwires at desired positions presents a significant challenge for developing high-density electronic devices. Here, we demonstrated the fabrication of cross-stacked pn heterojunction diode arrays by integrating well-aligned inorganic and organic microwires fabricated via evaporative assembly. We utilized solution-processed n-type inorganic indium–gallium–zinc-oxide (IGZO) microwires and p-type organic 6,13-bis­(triisopropylsilylethynyl)­pentacene (TIPS-PEN) microwires. The formation of organic TIPS-PEN semiconductor microwire and their electrical properties were optimized by controlling both the amounts of added insulating polymer and the widths of the microwires. The resulting cross-stacked IGZO/TIPS-PEN microwire pn heterojunction devices exhibited rectifying behavior with a forward-to-reverse bias current ratio exceeding 102. The ultrathin nature of the underlying n-type IGZO microwires yielded gate tunability in the charge transport behaviors, ranging from insulating to rectifying. The rectifying behaviors of the heterojunction devices could be modulated by controlling the optical power of the irradiated light. The fabrication of semiconducting microwires through evaporative assembly provides a facile and reliable approach to patterning or positioning 1D microwires for the fabrication of future flexible large-area electronics

Flexible and Transparent Metallic Grid Electrodes Prepared by Evaporative Assembly

We propose a novel approach to fabricating flexible transparent metallic grid electrodes via evaporative deposition involving flow-coating. A transparent flexible metal grid electrode was fabricated through four essential steps including: (i) polymer line pattern formation on the thermally evaporated metal layer onto a plastic substrate; (ii) rotation of the stage by 90° and the formation of the second polymer line pattern; (iii) etching of the unprotected metal region; and (iv) removal of the residual polymer from the metal grid pattern. Both the metal grid width and the spacing were systematically controlled by varying the concentration of the polymer solution and the moving distance between intermittent stop times of the polymer blade. The optimized Au grid electrodes exhibited an optical transmittance of 92% at 550 nm and a sheet resistance of 97 Ω/sq. The resulting metallic grid electrodes were successfully applied to various organic electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs), and organic solar cells (OSCs)

Combined EGCG/As treatment increases apoptosis in BAEC.

<p>(A) BAEC were treated with various doses (0, 5, 10, 20, 30, or 40 μM) of As or EGCG for 24 h. (B) In some experiments, cells were also treated for 24 h with 20 μM EGCG, 20 μM As, or the combination of 20 μM EGCG and As each (EGCG/As). (A, B) Cell viability was measured using MTT assay. (C, D) Cells treated with EGCG, As, or EGCG/As for 12 h. (C) Apoptotic cells were detected by DAPI staining. (D) Cells were lysed in RIPA buffer. An equal amount (20 μg) of each cell lysate was subjected to Western blot analysis. Levels of cleaved PARP expression were detected with an anti-cleaved PARP antibody. Quantifications were performed using densitometry (Image J software) and results were normalized to β-actin. (E-G) The activity of caspases (3, 8, and 9) was measured in cells treated with EGCG, As or EGCG/As for the specified times (0, 6, 12, 18, or 24 h). All line graphs represent the relative caspase activity of the control. (H) Assay for Bax translocation into the mitochondria. Cells treated with EGCG, As, or EGCG/As for 12 h were stained with FITC-conjugated anti-Bax antibody, Mitotracker as a marker of mitochondria, or DAPI. All bar graphs represent the mean ± S.D. of 3 independent experiments. The different characters refer to significant differences (<i>P <</i> 0.05) among groups, which were determined by one-way ANOVA followed by post hoc Student-Newman-Keuls analysis.</p

Petal-Inspired Diffractive Grating on a Wavy Surface: Deterministic Fabrications and Applications to Colorizations and LED Devices

Interestingly, the petals of flowering plants display unique hierarchical structures, in which surface relief gratings (SRGs) are conformably coated on a curved surface with a large radius of curvature (hereafter referred to as wavy surface). However, systematic studies on the interplay between the diffractive modes and the wavy surface have not yet been reported, due to the absence of deterministic nanofabrication methods capable of generating combinatorially diverse SRGs on a wavy surface. Here, by taking advantage of the recently developed nanofabrication composed of evaporative assembly and photofluidic holography inscription, we were able to achieve (i) combinatorially diverse petal-inspired SRGs with controlled curvatures, periodicities, and dimensionalities, and (ii) systematic optical studies of the relevant diffraction modes. Furthermore, the unique diffraction modes of the petal-inspired SRGs were found to be useful for the enhancement of the outcoupling efficiency of an organic light emitting diode (OLED). Thus, our systematic analysis of the interplay between the diffractive modes and the petal-inspired SRGs provides a basis for making more informed decisions in the design of petal-inspired diffractive grating and its applications to optoelectronics

Combined EGCG/As decreases the viability of two types of EC, HUVEC and HBMEC.

<p>(A) HUVEC were prepared and treated with various doses (0, 10, 20, 30, 40, 50 or 100 μM) of As or EGCG for 24 h. (B) In separate experiments, HUVEC were also treated with 50 μM EGCG, 10 μM As, or the combination of 50 μM EGCG and 10 μM As (EGCG/As) for 24 h. In some experiments, cells were pretreated with 5 mM NAC, 50 U/ml catalase or 1 μM SP600125 for 30 min prior to exposed to EGCG/As. (C) HBMEC were prepared and treated with various doses (0, 10, 20, 30, 40, 50 or 100 μM) of As or EGCG for 24 h. (D) In separate experiments, cells were also treated with 50 M EGCG, 50 μM As, or the combination of 50 μM EGCG and As each (EGCG/As) for 24 h. In separate experiments, cells were pretreated with 5 mM NAC, 50 U/ml catalase or 10 μM SP600125 for 30 min prior to exposed to EGCG/As. Cell viability was measured using MTT assay. All bar graphs represent the mean ± S.D. of 3–5 independent experiments. Statistical analysis was accomplished as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g001" target="_blank">Fig 1</a>.</p

NAC reverses cytotoxicity and pro-caspase activity induced by combined EGCG/As treatment.

<p>(A) BAEC were pretreated with various doses (0, 1, 5, or 10 mM) of NAC for 3 h prior to EGCG/As treatment for 24 h. (B-D) In separate experiments, EC were pretreated with the indicated dose (5 mM) of NAC. (E) In flow cytometric analysis, BAEC were pretreated with 20 μM Boc-D-FMK for 3 h prior to EGCG/As treatment for 12 h. (A) Cell viability, (B) caspase activity, (C) DAPI staining, (D) Bax translocation into the mitochondria, and (E) flow cytometric analyses were performed as described in the legend of Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g001" target="_blank">1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g002" target="_blank">2</a>. All bar graphs represent the mean ± S.D. of 3 independent experiments. Statistical analysis was accomplished as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g001" target="_blank">Fig 1</a>.</p

Schematic illustration of the molecular mechanism of EGCG/As-stimulated apoptosis of BAEC.

<p>(1) Combined EGCG/As treatment activates JNK. (2) Activated JNK decreases catalase activity. (3) Decreased catalase activity increases ROS (mainly H₂O₂) production in BAEC. (4) ROS activates pro-apoptotic machinery, consequently increasing EC apoptosis.</p

JNK mediates catalase activity, ROS production, and apoptosis altered by combined EGCG/As treatment.

<p>(A) BAEC were treated with EGCG/As for the indicated times (0, 0.5, 1, 2, or 3 h). (B) After pretreatment with catalase (50 U/ml) or the JNK inhibitor SP600125 (1 μM) for 30 min, EC were treated with EGCG/As for 1 h. The level of phosphorylated JNK (p-JNK) and total JNK protein was detected by Western blot analysis. (C) Cells were prepared and stained as described in the legends of Fig 5A and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g002" target="_blank">Fig 2</a>. In some experiments, cells were pretreated as described in the legend of Fig 5B, followed by treatment with EGCG/As for 3 h. Flow cytometric analysis was performed as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g002" target="_blank">Fig 2</a>. (D) Cell viability was determined as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g001" target="_blank">Fig 1</a> using BAEC pretreated with SP600125 prior to EGCG/As treatment for 24 h. (E) Catalase activity was measured as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g002" target="_blank">Fig 2</a> using BAEC pretreated with SP600125 prior to EGCG/As treatment for 2.5 h. (F, G) Cells were prepared, and pretreated with SP600125 (F) or MG132 (20 μM) (G) for 30 min prior to treatment of EGCG/As for 2.5 h. Cell lysate (30 μg) was subjected on 10% SDS-PAGE, and the level of catalase protein was then detected as described in <b>Materials and methods</b>. All bar graphs represent the mean±S.D. of 3 independent experiments. Statistical analysis was accomplished as described in the legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138590#pone.0138590.g001" target="_blank">Fig 1</a>.</p