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. The incorporation of dioctyl sulfosuccinate sodium salt (DOSS) significantly improves the capacitance and sensing properties by forming an electrical double-layer through interactions between the electrode charge and salt ions at the contact interface. The developed polymer material-based tactile sensor shows a strong response signal at low pressure (0.1 kPa) and maintains high sensitivity (0.175 kPa-1) over a wide pressure range (0.1-10 kPa). It also maintains the same sensitivity over 10 000 repeated applications of external pressure and is easily self-healed against mechanical deformation due to the dynamic disulfide covalent bonding, restoring ≈95% of its detection capacity.

Characterization of Porous CuO Films for H2S 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). Relative density and porosity were quantitatively calculated. CuO films with various pores ranging from 39.4 to 95.2% were successfully manufactured and were applied as gas sensors for H2S detection on interdigitated electrode (IDE) substrate. Resistance change was monitored at 325 °C and an increase in porosity of the film improved the sensor performance. The CuO-10 gas sensor with a high porosity of 95.2% showed a relatively high response (2.7) and a fast recovery time (514 s) for H2S 1.5 ppm. It is confirmed that the porosity of the CuO detection layer had a significant effect on response and recovery time.

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. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions: The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy.

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. Subsequently, a Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, λ = 1064 nm) laser is employed for the direct ablation of the ITO/Ag/ITO ML films to pattern ITO/Ag/ITO ML electrodes. Analysis of the laser-patterned results indicate that the ITO/Ag/ITO ML films exhibit wider ablation widths and lower ablation thresholds than ITO single layer (SL) films. However, the dependence of Ag thickness on the laser patterning results of the ITO/Ag/ITO MLs is not observed, despite the difference in their absorption coefficients. The results show that the laser direct patterning of ITO/Ag/ITO MLs is primarily affected by rapid thermal heating, melting, and vaporization of the inserted Ag mid-layer, which has considerably higher thermal conductivity and absorption coefficients than the ITO layers. Simulation reveals the importance of the Ag mid-layer in the effective absorption and focusing of photothermal energy, thereby supporting the experimental observations. The laser-patterned ITO/Ag/ITO ML electrodes indicate a comparable optical transmittance, a higher electrical current density, and a lower resistance compared with the ITO SL electrode.

Cross-Linked Composite Gel Polymer Electrolyte Based on an H-Shaped Poly(ethylene oxide)-Poly(propylene oxide) Tetrablock Copolymer with SiO2 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, SiO2 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 SiO2 surface. The incorporation of an optimal amount of SiO2 increased the cross-linking density of the resulting CGPE while reducing polymer-chain ordering and, consequently, increasing both ionic conductivity and mechanical strength. As a result, the CGPE with 0.1 wt % SiO2 exhibited a high ionic conductivity (2.22 × 10-3 S cm-1 at 25 °C), good tensile strength (453 kPa), and high thermal stability up to 330 °C. Finally, an all-solid-state SC assembled with the prepared CGPE showed a high operating voltage (3 V), a large specific capacitance (103.9 F g-1 at 1 A g-1), and excellent durability (94% capacitance retention over 10,000 charge/discharge cycles), which highlights its strong potential as a solid-state electrolyte for SCs.

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. A comparison of the results of the laser ablation of such a graphene/ITO double layer with those of the ITO single-layered films reveals that a larger amount of effective thermal energy of the laser used is transferred in the lateral direction along the graphene upper layer in the graphene/ITO double-layered structure, attributable to the high thermal conductivity of graphene. The transferred thermal energy is expected to melt and evaporate the lower ITO layer at a relatively lower threshold energy of laser ablation. The transient analysis of the temperature profiles indicates that the graphene layers can act as both an effective thermal diffuser and converter for the planar heat transfer. Raman spectroscopy was used to investigate the graphite peak on the ITO layer where the graphene upper layer was selectively removed because of the incomplete heating and removal process for the ITO layer by the laterally transferred effective thermal energy of the laser beam. Our approach could have broad implications for designing highly transparent and conductive electrodes as well as a new way of nanoscale patterning for other optoelectronic-device applications using laser-ablation methods.

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. Applying an electrical bias to an aqueous solution of alkali metal halides placed at the end of an SWNT array causes ionic transport along the exterior of SWNTs and the subsequent formation of salt micro/nanocrystals. The crystals serve as micro/nanolenses that optically visualize individual SWNTs and amplify their Raman scattering by orders of magnitude. Molecules dissolved in the ionic solution can be electrokinetically transported along the nanotubes, captured within the lenses, and analyzed by Raman spectroscopy, which we demonstrate by detecting ∼12 attomoles of glucose and 2 femtomoles of urea. The hygroscopic salt nanolenses are robust under various ambient conditions indefinitely, by transitioning to liquid droplets above their deliquescence relative humidity, yet can be removed nondestructively by water. Our approach could have broad implications in the optical visualization of 1D nanostructures, molecular transport or chemical reactions in 1D space, and molecular spectroscopy in salty environments.

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. Moreover, since the SFG is charged by an embedded tunneling field-effect transistor existing between the channel and the drain junction when the post-synaptic spike occurs after the pre-synaptic spike, and vice versa, the SFG is discharged by the diode when the post-synaptic spike takes place before the pre-synaptic spike. This indicates that the SFGST can attain STP/LTP and spike-timing-dependent plasticity behaviors. These characteristics of the SFGST in the highly miniaturized transistor structure can contribute to the neuromorphic chip such that the total system may operate as fast as the human brain with low power consumption and high integration density.

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. The possibilities of the program operation by impact ionization and the erase operation via drift conduction by a properly high drain voltage have been verified through a series of technology computer-aided design (TCAD) device simulations at 500 K. Analyses of the energy-band structures in the hold state reveals that the electrons stored in the channel can be effectively confined and retained by the surrounding thin wide-bandgap semiconductor barriers. Additionally, for more realistic and practical claims, transient characteristics of the proposed volatile memory device have been closely investigated quantifying the programming window and retention time. Although there is an inevitable degradation in state-1/state-0 current ratio compared with the case of room-temperature operation, the high-temperature operation capabilities of the proposed memory device at 500 K have been confirmed to fall into the regime permissible for practical use.

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. Process conditions for these WS2 thin films on sapphire substrate were optimized to low RF sputtering power and high temperature annealing.

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). These peaks were blue-shifted compared to the reported literature values and are attributed to the quantum confinement effect. Interestingly, the WS2 nanosheets exhibited the same characteristic absorption peak at ~624 nm (1.99 eV). Raman spectroscopy analysis revealed that both nanosheets displayed distinctive peaks [377.8 cm-1 and 405.6 cm-1 for MoS2, 348.3 cm-1 and 417.9 cm-1 for WS2] that originate from optical phonon modes (E12g and A1g). These peaks are shifted toward higher wavenumbers (i.e., blue-shift or phonon-stiffening) compared to bulk MoS2 and WS2, probably due to enhanced Stokes Raman scattering. Subsequently, surface functionalization of the nanosheets with 2-Mercaptoethanol was successfully performed and confirmed using optical characterization techniques, including FT-IR spectroscopy. In addition, we determined the spectral broadening after functionalization, which would be attributed to photon confinement of the nano-sized layer structure, or to inhomogeneous broadening.

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. Although saving energy and enhancing energy efficiency is one of the most important issues, the application approach to harvesting wasted energy without compromising the reliability of existing mechanical systems is still in very early stages. Here, we report of a new type of TEG, a suspension-type free-standing mode TEG (STEG) inspired from a shock absorber in a suspension system. We discovered that the optimum width of electrode output voltage was 131.9 V and current was 0.060 µA/cm² in root mean square (RMS) value while the optimized output power was 4.90 µW/cm² at 66 MΩ. In addition, output power was found to be proportional to frictional force due to the contact area between two frictional surfaces. It was found that the STEG was made of perfluoroalkoxy film and showed good mechanical durability with no degradation of output performance after sliding 11,000 times. In addition, we successfully demonstrated charging a capacitor of 330 µF in 6 min.

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 (5.0 × 10-3 S cm-1) and good mechanical stability (maximum strain = 194%). Moreover, our polymer electrolytes have various advantages including high thermal stability (decomposition temperature > 330 °C) and the capability to impregnate electrodes to form an excellent electrode-electrolyte interface due to the very low viscosity of the precursors. By assembling our GPE-impregnated electrodes and solid-state GPE film, we demonstrate an all-solid-state SC that can operate at 3 V and provides an improved specific capacitance (112.3 F g-1 at 0.1 A g-1), better rate capability (64% capacity retention until 20 A g-1), and excellent cycle stability (95% capacitance decay over 10 000 charge/discharge cycles) compared with those of a reference SC using a conventional PEO electrolyte. Finally, flexible SCs with a high energy density (22.6 W h kg-1 at 1 A g-1) and an excellent flexibility (>93% capacitance retention after 5000 bending cycles) can successfully be obtained.

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. The results showed that the laser-ablated widths on the graphene/photopolymer double layer were much greater than those on the graphene monolayer, especially at lower scanning speeds and at higher repetition rates. The photopolymer layer was not removed by the laser ablation, and the thermal energy was considered to have been dissipated in the lateral direction of graphene instead of being conducted vertically to the glass substrate. The Raman spectrum results showed that the graphene layer was clearly removed on the laser-ablated region of interest.

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. We provide a possible explanation in terms of several factors: dispersion of laser beam energy through the substrate, overlapping of each laser beam spot due to scanning speed, and the thickness of glass and PET substrates.

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. In this study, we demonstrate that the alignment of core nanomaterials can significantly influence a number of aspects of the thermopower waves, while the nanomaterials involved are identical carbon nanotubes (CNTs). Diversely structured, large-area CNT/fuel composites of one-dimensional aligned CNT arrays (1D CNT arrays), randomly oriented CNT films (2D CNT films), and randomly aggregated bulk CNT clusters (3D CNT clusters) were fabricated to evaluate the energy generation, as well as the propagation of the thermal wave, from thermopower waves. The more the core nanostructures were aligned, the less inversion of temperature gradients and the less cross-propagation of multiple thermopower waves occurred. These characteristics of the aligned structures prevented the cancellation of charge carrier movements among the core nanomaterials and produced the relative enhancement of the energy generation and the specific power with a single-polarity voltage signal. Understanding this effect of structure on energy generation from thermopower waves can help in the design of optimized hybrid composites of nanomaterials and fuels, especially designs based on the internal alignment of the materials. More generally, we believe that this work provides clues to the process of chemical to thermal to electrical energy conversion inside/outside hybrid nanostructured materials.

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. For this reason, in accordance, processing technology should be evolved with higher reliability and accuracy, and compatibility with the conventional unit processes including electron beam (e-beam) lithography, plasma etching, and nano-dimensional optical lithography. In this work, a reliable, simple, and cost-effective technique for patterning the graphene is proposed. Graphene film transferred on glass substrate is directly patterned by a quality factor (Q)-switched neodymium-doped yttrium vanadate (Nd:YVO4, λ = 1064 nm) pumped laser diode (LD). In order to optimize the process condition, various beaming conditions of repetition rate and scanning speed are experimented. From the optical microscope images, it has been shown that graphene film was more easily etched by direct laser patterning technique at higher repetition and faster scanning speed. It was confirmed by Raman spectrum where 2-dimensional (2-D) and graphite (G) peaks were closely investigated that graphene residue was also completely removed after the proposed processing technique.

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. The CLA isomers significantly enhanced GJIC of MCF-7 cells at 40 µ M concentration, whereas CLA inhibited cell growth and induced caspase-dependent apoptosis. CLA increased connexin43 (Cx43) expression both at the transcriptional and translational levels. CLA inhibited nuclear factor- κ B (NF- κ B) activity and enhanced reactive oxygen species (ROS) generation. No significant difference was observed in the efficacy of c9,t11-CLA and t10,c12-CLA. These results suggest that the anticancer effect of CLA is associated with upregulation of GJIC mediated by enhanced Cx43 expression through inactivation of NF- κ B and generation of ROS in MCF-7 cells.

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. However, residual spikes (about 50 nm in height) of ITO were found to be formed at the edges of the laser ablated area and a few ITO residues remained on the glass substrate after laser scanning. By dipping the laser-ablated ITO film in ITO diluted etchant (ITO etchant/DI water: 1/10) at 50 degrees C for 3 min, the spikes and residual ITO were effectively removed. At last, using the laser direct patterning, a bottom-source-drain indium gallium zinc oxide thin film transistor (IGZO-TFT) was fabricated. It is successfully demonstrated that the laser direct patterning can be utilized instead of photolithography to simplify the fabrication process of TFT channel, resulting in the increase of productivity and reduction of cost.

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. As the thermal conductivity of glass substrate is about 7.5 times higher than that of PET, more thermal energy would be spread and transferred to lateral direction in the ITO film in case of PET substrate.