In Situ Raman Spectroscopy-Enabled Microfluidic Gel Chromatography for Revealing Real-Time Separation Dynamics of Single-Walled Carbon Nanotubes.

Single-walled carbon nanotubes (SWNTs) exhibit distinct electronic properties, categorized as metallic or semiconducting, determined by their chirality. The precise and selective separation of these electronic types is pivotal for advancing nanotechnology applications. While conventional gel chromatography has been widely employed for large-scale separations, its limitations in addressing microscale dynamics and electronic-type differentiation have persisted.

White Light-Emitting Flexible Displays with Quantum-Dot Film and Greenish-Blue Organic Light-Emitting Diodes.

White organic light-emitting diodes (OLEDs) represent a significant technology in the display industry for the achievement of full color. However, sophisticated technologies are required for white light emission. In this paper, we developed a simple white light-emitting display device using a quantum-dot (QD) film and a greenish-blue OLED.

Synthesis of Highly Porous Graphene Oxide-PEI Foams for Enhanced Sound Absorption in High-Frequency Regime.

High-frequency noise exceeding 1 kHz has emerged as a pressing public health issue in industrial and occupational settings. In response to this challenge, the present study explores the development of a graphene oxide-polyethyleneimine (GO-PEI) foam (GPF) featuring a hierarchically porous structure. The synthesis and optimization of GPF were carried out using a range of analytical techniques, including Raman spectroscopy, scanning electron microscopy (SEM), Braunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR).

Dynamic Covalent Bond-Based Polymer Chains Operating Reversibly with Temperature Changes.

Dynamic bonds can facilitate reversible formation and dissociation of connections in response to external stimuli, endowing materials with shape memory and self-healing capabilities. Temperature is an external stimulus that can be easily controlled through heat. Dynamic covalent bonds in response to temperature can reversibly connect, exchange, and convert chains in the polymer.

Synthesis of PDMS Chain Structure with Introduced Dynamic Covalent Bonding for High-Performance Rehealable Tactile Sensor Application.

In addressing the increasing demand for wearable sensing systems, the performance and lifespan of such devices must be improved by enhancing their sensitivity and healing capabilities. The present work introduces an innovative method for synthesizing a healable disulfide bond contained in a polydimethylsiloxane network (PDMS-SS) that incorporates ionic salts, which is designed to serve as a highly effective dielectric layer for capacitive tactile sensors. Within the polymer network structure, the cross-linking agent pentaerythritol tetrakis 3-mercaptopropionate (PTKPM) forms reversible disulfide bonds while simultaneously increasing polymer softness and the dielectric constant.

Characterization of Porous CuO Films for HS Gas Sensors.

Using a thermal evaporator, various porous Cu films were deposited according to the deposition pressure. CuO films were formed by post heat treatment in the air. Changes in morphological and structural characteristics of films were analyzed using field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD).

Correlation between Surrogate Quality Indicators for Adenoma Detection Rate and Adenoma Miss Rate in Qualified Colonoscopy, CORE Study: KASID Multicenter Study.

Background/aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested. This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy.

Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists.

Effects of Insertion of Ag Mid-Layers on Laser Direct Ablation of Transparent Conductive ITO/Ag/ITO Multilayers: Role of Effective Absorption and Focusing of Photothermal Energy.

From the viewpoint of the device performance, the fabrication and patterning of oxide-metal-oxide (OMO) multilayers (MLs) as transparent conductive oxide electrodes with a high figure of merit have been extensively investigated for diverse optoelectronic and energy device applications, although the issues of their general concerns about possible shortcomings, such as a more complicated fabrication process with increasing cost, still remain. However, the underlying mechanism by which a thin metal mid-layer affects the overall performance of prepatterned OMO ML electrodes has not been fully elucidated. In this study, indium tin oxide (ITO)/silver (Ag)/ITO MLs are fabricated using an in-line sputtering method for different Ag thicknesses on glass substrates.

Cross-Linked Composite Gel Polymer Electrolyte Based on an H-Shaped Poly(ethylene oxide)-Poly(propylene oxide) Tetrablock Copolymer with SiO Nanoparticles for Solid-State Supercapacitor Applications.

Achieving high ionic conductivity, wide voltage window, and good mechanical strength in a single material remains a key challenge for polymer-based electrolytes for use in solid-state supercapacitors (SCs). Herein, we report cross-linked composite gel polymer electrolytes (CGPEs) based on multi-cross-linkable H-shaped poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) tetrablock copolymer precursors, SiO nanoparticles, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, an ionic liquid (IL). Self-standing CGPE membranes with a high IL content were prepared using in situ cross-linking reactions between the silane groups present in the precursor and the SiO surface.

Understanding of the Mechanism for Laser Ablation-Assisted Patterning of Graphene/ITO Double Layers: Role of Effective Thermal Energy Transfer.

Demand for the fabrication of high-performance, transparent electronic devices with improved electronic and mechanical properties is significantly increasing for various applications. In this context, it is essential to develop highly transparent and conductive electrodes for the realization of such devices. To this end, in this work, a chemical vapor deposition (CVD)-grown graphene was transferred to both glass and polyethylene terephthalate (PET) substrates that had been pre-coated with an indium tin oxide (ITO) layer and then subsequently patterned by using a laser-ablation method for a low-cost, simple, and high-throughput process.

Hygroscopic Micro/Nanolenses along Carbon Nanotube Ion Channels.

Nanolenses of alkali metal halides can be a unique optical element due to their hygroscopicity, optical transparency, and high mobility of constituent ions. It has been challenging, however, to form and place such lenses in a controlled manner. Here, we report micro/nanolenses of various alkali metal halides arranged as a one-dimensional (1D) array, using the exterior of single-walled carbon nanotubes (SWNTs) as a template for forming the lenses.

Design and Characterization of Semi-Floating-Gate Synaptic Transistor.

In this work, a study on a semi-floating-gate synaptic transistor (SFGST) is performed to verify its feasibility in the more energy-efficient hardware-driven neuromorphic system. To realize short- and long-term potentiation (STP/LTP) in the SFGST, a poly-Si semi-floating gate (SFG) and a SiN charge-trap layer are utilized, respectively. When an adequate number of holes are accumulated in the SFG, they are injected into the nitride charge-trap layer by the Fowler⁻Nordheim tunneling mechanism.

Cylindrical Free-Standing Mode Triboelectric Generator for Suspension System in Vehicle.

The triboelectric generator (TEG) is a strong candidate for low-power sensors utilized in the Internet of Things (IoT) technology. Within IoT technologies, advanced driver assistance system (ADAS) technology is included within autonomous driving technology. Development of an energy source for sensors necessary for operation becomes an important issue, since a lot of sensors are embedded in vehicles and require more electrical energy.

A Novel One-Transistor Dynamic Random-Access Memory (1T DRAM) Featuring Partially Inserted Wide-Bandgap Double Barriers for High-Temperature Applications.

These days, the demand on electronic systems operating at high temperature is increasing owing to bursting interest in applications adaptable to harsh environments on earth, as well as in the unpaved spaces in the universe. However, research on memory technologies suitable to high-temperature conditions have been seldom reported yet. In this work, a novel one-transistor dynamic random-access memory (1T DRAM) featuring the device channel with partially inserted wide-bandgap semiconductor material toward the high-temperature application is proposed and designed, and its device performances are investigated with an emphasis at 500 K.

Surface Functionalization of Liquid-Phase Exfoliated, Two-Dimensional MoS₂ and WS₂ Nanosheets with 2-Mercaptoethanol.

In this work, the UV-Vis-NIR absorption spectrum of liquid-phase exfoliated two-dimensional (2D) MoS2 nanosheets, revealed two prominent peaks at 608 nm (2.04 eV) and 668 nm (1.86 eV).

A Study on the Formation of 2-Dimensional Tungsten Disulfide Thin Films on Sapphire Substrate by Sputtering and High Temperature Rapid Thermal Processing.

As direct formation of p-type two-dimensional transition metal dichalcogenides (TMDC) films on substrates, tungsten disulfide (WS2) thin films were deposited onto sapphire glass substrate through shadow mask patterns by radio-frequency (RF) sputtering at different sputtering powers ranging from 60 W to 150 W and annealed by rapid thermal processing (RTP) at various high temperatures ranging from 500 °C to 800 °C. Based on scanning electron microscope (SEM) images and Raman spectra, better surface roughness and mode dominant E12g and A1g peaks were found for WS2 thin films prepared at higher RF sputtering powers. It was also possible to obtain high mobilities and carrier densities for all WS2 thin films based on results of Hall measurements.

Electrode-Impregnable and Cross-Linkable Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Polymer Electrolytes with High Ionic Conductivity and a Large Voltage Window for Flexible Solid-State Supercapacitors.

We present cross-linkable precursor-type gel polymer electrolytes (GPEs) that have large ionic liquid uptake capability, can easily penetrate electrodes, have high ion conductivity, and are mechanically strong as high-performance, flexible all-solid-state supercapacitors (SC). Our polymer precursors feature a hydrophilic-hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock main-chain structure and trifunctional silane end groups that can be multi-cross-linked with each other through a sol-gel process. The cross-linked solid-state electrolyte film with moderate IL content (200 wt %) shows a well-balanced combination of excellent ionic conductivity (5.

Laser Direct Ablation of Indium Tin Oxide Films on Both Sides of Various Substrates.

We demonstrate ablation of indium tin oxide (ITO) films onto both glass and polyethylene terephthalate (PET) substrates, using a Q-switched diode-pumped neodymium-doped yttrium vanadate laser (Nd:YVO4, λ = 1064 nm) incident on both the front and back sides of the substrate. From scanning electron microscope (SEM) images and depth profile data, ITO patterns that were laser-ablated onto glass from the back side showed a larger abrupt change in the ablated line width than those ablated from the front. However, there were only slight differences in ablated line widths due to the direction of the incident laser beam.

Direct Ablation by Laser of Single Graphene Monolayer and Graphene/Photopolymer Double Layer.

A diode-pumped Q-switched neodymium-doped yttrium vanadate (Nd:YVO4, λ = 1064 nm) laser was applied to obtain graphene patterns on a photopolymer layer by direct ablation. In the transfer process of the graphene layer, the photopolymer was employed as a graphene supporting layer and it was not removed for the simplification of the process. The laser ablation was carried out on graphene/photopolymer double layers for various beam conditions.

Ablation of graphene film by direct Nd:YVO4 laser under various beaming conditions.

Recently, graphene is gaining increasing popularity as one of the most functional materials for advanced electronic and optical devices owing to its high carrier mobility and optical transparency. Patterning the graphene calls for particular cares in line definition without carbon (C)-based residues that might be working as a leakage path. Thus, realization and processing of the graphene monolayer are very complicated and need to be stringently controlled.

Investigation of the effect of the structure of large-area carbon nanotube/fuel composites on energy generation from thermopower waves.

Thermopower waves are a recently developed energy conversion concept utilizing dynamic temperature and chemical potential gradients to harvest electrical energy while the combustion wave propagates along the hybrid layers of nanomaterials and chemical fuels. The intrinsic properties of the core nanomaterials and chemical fuels in the hybrid composites can broadly affect the energy generation, as well as the combustion process, of thermopower waves. So far, most research has focused on the application of new core nanomaterials to enhance energy generation.

Antiproliferative Action of Conjugated Linoleic Acid on Human MCF-7 Breast Cancer Cells Mediated by Enhancement of Gap Junctional Intercellular Communication through Inactivation of NF- κ B.

The major conjugated linoleic acid (CLA) isomers, c9,t11-CLA and t10,c12-CLA, have anticancer effects; however, the exact mechanisms underlying these effects are unknown. Evidence suggests that reversal of reduced gap junctional intercellular communication (GJIC) in cancer cells inhibits cell growth and induces cell death. Hence, we determined that CLA isomers enhance GJIC in human MCF-7 breast cancer cells and investigated the underlying molecular mechanisms.

Laser direct patterning of indium tin oxide for defining a channel of thin film transistor.

In this work, using a Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, lambda = 1064 nm) laser, a direct patterning of indium tin oxide (ITO) channel was realized on glass substrates and the results were compared and analyzed in terms of the effect of repetition rate, scanning speed on etching characteristics. The results showed that the laser conditions of 40 kHz repetition rate with a scanning speed of 500 mm/s were appropriate for the channeling of ITO electrodes. The length of laser-patterned channel was maintained at about 55 microm.

Nd:YVO4 laser direct ablation of indium tin oxide films deposited on glass and polyethylene terephthalate substrates.

A Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, lambda = 1064 nm) laser was applied to obtain the indium tin oxide (ITO) patterns on flexible polyethylene terephthalate (PET) substrate by a direct etching method. After the ITO films were deposited on a soda-lime glass and PET substrate, laser ablations were carried out on the ITO films for various conditions and the laser ablated results on the ITO films were investigated and analyzed considering the effects of substrates on the laser etching. The laser ablated widths on ITO deposited on glass were found to be much narrower than those on ITO deposited on PET substrate, especially, at a higher scanning speed of laser beam such as 1000 mm/s and 2000 mm/s.

Nanomechanical characterization of chemical interaction between gold nanoparticles and chemical functional groups.

We report on how to quantify the binding affinity between a nanoparticle and chemical functional group using various experimental methods such as cantilever assay, PeakForce quantitative nanomechanical property mapping, and lateral force microscopy. For the immobilization of Au nanoparticles (AuNPs) onto a microscale silicon substrate, we have considered two different chemical functional molecules of amine and catecholamine (here, dopamine was used). It is found that catecholamine-modified surface is more effective for the functionalization of AuNPs onto the surface than the amine-modified surface, which has been shown from our various experiments.