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We report the cause of degradation of low-temperature amorphous indium-gallium-zinc-oxide (a-IGZO) coplanar thin-film transistors (TFTs). As the deposition temperature of the buffer layer was changed from 400 to 200 °C, the field-effect mobility decreased considerably from 15 to 3 cm2 V−1 s−1, the subthreshold swing (SS) increased from ~ 150 to 280 mV dec−1, the threshold voltage shift (ΔVth) under negative bias temperature stress (NBTS) increased from − 0.27 to − 0.33 V, and ΔVth under a positive bias temperature stress (PBTS) increased significantly from 0 to 4.9 V. From the results of high-resolution transmission electron microscopy (HR-TEM) and X-ray reflectivity (XRR), the poor roughness created by sputtering damage of the interface between the gate insulator (GI) and the a-IGZO is the cause of degradation. In addition, through an atomic probe tomography (APT) analysis, the reason low-temperature TFTs have poorer PBTS stability than NBTS is carefully to be due to zinc (Zn)-related defects that create ionized oxygen vacancies. Based on these results, we introduce strategies for realizing low-temperature oxide TFTs using vacuum process. Please confirm if the author names are presented accurately and in the correct sequence as given name, middle name/initial, family name. Also, kindly confirm the details in the metadata are correct. We confirmed all author names. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. We checked all authors and their affiliations.

Manganese-based catalysts have attracted much attention due to their excellent performance for NO reduction with NH3 (NH3-SCR) at low temperatures. In the current study, the novel metal Sb was modified into Mn/TiO2 and Fe–Mn/TiO2, and the NO x conversion was compared with those of Mn/TiO2 and Fe–Mn/TiO2 catalysts to investigate the effect of the Sb. The NO x reduction activities of the catalysts were evaluated in the temperature range of 100–250 °C at a space velocity of 60,000 h−1. The physicochemical properties of all the catalysts were characterized by Brunauer–Emmett–Teller surface area, temperature-programmed desorption of ammonia, temperature-programmed reduction, X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. Interestingly, the Sb-promoted Mn-based catalysts showed significantly higher NO x conversion than the other catalysts with or without 6 vol% of H2O. The high performance of the Sb-modified catalysts could be related to the increase of acid sites and redox properties.

Recently, many researchers have focused on wireless microrobots as therapeutic agents for active drug delivery. Owing to their size limitation, they cannot be equipped with actuators/sensors, controllers and batteries. Therefore, external devices (magnetic field generator, position recognition devices, and control system) are used to realize the main functions (locomotion, sensing, and therapy) of biomedical microrobots and thus, to minimize their size. Especially, the small wireless microrobots, inserted into the human body, should have various steering, locomotive, and therapeutic functions for diagnosis and treatment. Generally, an external magnetic field is widely used for the locomotion of a wireless microrobot. However, microrobots using an external magnetic field cannot simultaneously realize equitranslational and axial rotational motions in the same microrobot system. In this paper, we developed an electromagnetic actuation (EMA) system and a spiral-shape microrobot and proposed its actuating algorithm. The developed wireless microrobot can show equitranslation and axial rotation in the same microrobot system. Finally, various experiments in a test-bed and in a blood vessel phantom validated that the developed microrobot can move to a target position by equitranslation and can penetrate a thrombus model by axial rotation.

The direct emission of circularly polarized (CP) light improves the efficiency of an organic light-emitting diode and characterizes the secondary structure of proteins. In most cases, CP light is generated from a luminescent layer containing chiral characteristics, thereby generating only one kind of CP light in an entire device. Here, we propose direct CP light emissions using a twisted achiral conjugate polymer without any chiral dopant as an emitting layer (EML). The twisted structure is induced in the mesogenic conjugate polymer due to its elasticity by applying different alignment directions to its upper and lower interfaces. Furthermore, we demonstrate the simultaneous emission of orthogonal CP light in a single luminescent device by patterning different alignment directions on the surfaces of the EML. The light source with multipolarization including the orthogonal CP states is applicable to many applications in biosensors and optical devices., Simultaneous right and left circular polarization from single device Both right- and left-handed circularly polarized light were generated from a single device, paving the way for novel applications in biosensors and organic LEDs. Chang-Jae Yu of Hanyang University in Korea and colleagues fabricated the device by using the liquid crystal phase of a polymer, called F8BT, which is commonly used in organic light-emitting diodes. They controlled the alignment of the molecules inside the polymer by rubbing its upper and lower surfaces in specific directions. The rubbing caused the molecules inside the polymer to align and twist. Light passing through the polymer simultaneously emerges as right- and left-handed circularly moving electromagnetic waves. The study demonstrates the feasibility of a light source with multiple polarizations, which could have applications in a variety of optical devices.

In this paper, we proposed a magnetically steerable guidewire device composed of two parts: steering part and feeding part. The steering part consists of a magnet attached to the end of a commercial guidewire and 2-pair Helmholtz coils, and the feeding part consists of a motorized stage and a device for holding the guidewire. In detail, the 2-pair Helmholtz coils generate a uniform magnetic field that can align the guidewire magnet in the region of interest (ROI) along a desired direction. In addition, the feeding part remotely controls guidewire insertion and the length of the flexible part of the guidewire extruded from a catheter. For accurate alignment at the end of the guidewire, we controlled the flexible length of the guidewire extruded from a catheter and the intensity and direction of the uniform magnetic field using the feed-forward method. In addition, to reduce alignment error due to unpredicted disturbances and friction effects between the test-bed and the guidewire, proportional-integralderivative control is introduced as a feedback control algorithm. Using the control algorithms, we demonstrated accurate actuation of the steerable guidewire device with a steering angle error of less than 0:5◦. We expect that the proposed steerable guidewire device can be applied to the development of a 3-D locomotive guidewire with position recognition for percutaneous coronary intervention (PCI).

Recently, due to a lack of exercise and aging, cardiovascular disease has become a major cause of death worldwide. Drug therapy and surgical operation have been widely used to treat cardiovascular disease. However, the treatment of chronic total occlusions (CTOs) through clinical operation still remains a considerable challenge, as CTOs have stiff proximal fibrous caps on their ends, which can be a serious barrier for a conventional operation using guide wires or biomedical devices. Through the analysis of the composition and physical properties of CTOs, we synthesized an artificial CTO composition consisting of collagen, blood, CaCO3, and levo-polylactic acid polymer. The artificial CTO composition was inserted into an arterial segment of swine, and a final CTO artery model was obtained. For the feasibility test of an extracorporeal shock wave lithotripsy (ESWL) device for CTO therapy, we adopted ESWL equipment with a C-arm X-ray fluoroscope. Through the feasibility tests, the optimal parameters of the ESWL equipment were found: an energy level of 4 (16.7–17.2 kV) and a total of 1000 shock waves. A tunneling efficiency of 85 % was achieved with the optimal parameters. We also tested the tunneling efficiency according to increased tissue thickness with the optimal parameters; the tunneling efficiency was reduced when the tissue thickness was increased, but the tunneling efficiency remained at 62 % for a tissue thickness of 3 cm. In addition, the final remaining clot ranged in size from 3 to 183 μm, which was observed using a Nikon Ti-U microscope and analyzed using ImageJ. The safety of ESWL treatment was also confirmed through pathological analysis. Consequently, we expect that ESWL might become an effective therapeutic method for the tunneling of CTO.

This paper proposes a locomotive, therapeutic microrobot based on an electromagnetic actuation (EMA) system for intravascular treatment. The proposed EMA system consists of the two pairs of stationary Helmholtz and Maxwell coils along the x-axis and two pairs of rotational uniform saddle coil (USC) and gradient saddle coil (GSC) about the x-axis. A microrobot actuated by this type of EMA system can be used as a locomotive, therapeutic microrobot in medical applications. Especially, when we apply sinusoidal currents to the Maxwell coil and GSC pairs, the microrobot shows oscillatory forward and backward motion (which is called as hammering motion); however, when sinusoidal voltages are applied to the Maxwell coil and GSC pairs, the microrobot does not show the desired hammering motion. W proposes a compensation algorithm for the resistance and inductance variations and demonstrates the desired hammering motion for the effective therapeutic function of the microrobot. Through various experiments, we validate that the proposed microrobot using the EMA system can show precise locomotion and provide enhanced treatment.

Electromagnetic-actuated robotic systems have been studied recently for special purposes. Because these systems use external magnetic fields to control their robots, the robots can have simple structures and move with much freedom. In particular, these electromagnetic actuation (EMA) systems are being widely adopted for the actuation of biomedical mini-robots and microrobots for minimally invasive surgery (MIS) and diagnosis. We previously reported, as a feasible biomedical robot, the biomimetic swimming tadpole mini-robot, which can only swim above water. Indeed, the two-dimensional (D) plane swimming tadpole mini-robot is limited in its use because of its motility in the 2D plane. Therefore, this paper proposes a 3D swimming tadpole mini-robot that can move freely in water. First, in the proposed 3D swimming tadpole mini-robot, the buoyancy force was regulated for subaqueous swimming, and the permanent magnet was rearranged for precise movement. Second, to attain a 3D swimming motion, the actuation mechanism of the robot was developed using an EMA system. Finally, various experiments verified that the proposed 3D swimming tadpole mini-robot can swim freely in a 3D water environment.

With the goal of developing an accurate and fast lane tracking system for the purpose of driver assistance, this paper proposes a vision-based fusion technique for lane tracking and forward vehicle detection to handle challenging conditions, i.e., lane occlusion by a forward vehicle, lane change, varying illumination, road traffic signs, and pitch motion, all of which often occur in real driving environments. First, our algorithm uses random sample consensus (RANSAC) and Kalman filtering to calculate the lane equation from the lane candidates found by template matching. Simple template matching and a combination of RANSAC and Kalman filtering makes calculating the lane equation as a hyperbola pair very quick and robust against varying illumination and discontinuities in the lane. Second, our algorithm uses a state transfer technique to maintain lane tracking continuously in spite of the lane changing situation. This reduces the computational time when dealing with the lane change because lane detection, which takes much more time than lane tracking, is not necessary with this algorithm. Third, false lane candidates from occlusions by frontal vehicles are eliminated using accurate regions of the forward vehicles from our improved forward vehicle detector. Fourth, our proposed method achieved robustness against road traffic signs and pitch motion using the adaptive region of interest and a constraint on the position of the vanishing point. Our algorithm was tested with image sequences from a real driving situation and demonstrated its robustness.

Li1+x V1−x O2 (0 ≤ x ≤ 0.1) compounds were studied as the anode materials for a lithium-ion battery. The crystal and electronic structures of the prepared materials were correlated with electrical conductivities and electrochemical properties. The electrochemical behaviors were significantly dependent on the composition of Li1+x V1−x O2, and these were resulted from the perturbation of the local electronic structure arising from the increase in lithium contents in Li1+x V1−x O2 rather than from the slight distortion in the crystal structure. The electrical conductivities of Li1+x V1−x O2 increased with the increase in lithium contents in the compounds. Li1.1V0.9O2 and Li1.075V0.925O2 samples exhibit the first discharge capacities of 250 and 241 mAh g−1 at 0.2 C-rate, respectively.

The overall driving environment consists of the Traffic environment, vehicle and driver states (TVD). advanced driver assistance Systems (ADAS) must consider not only information on each of the TVD states but also their context. Recent research has focused on making more efficient and effective assistance systems by fusing all the information from the TVD states. Based on this research trend, this paper focuses on decision-level fusion to estimate the level of danger of a warning by using visual information of the traffic environment and the driver state. The driver state consists of the gazing region and the facial feature points that are obtained using the active appearance model (AAM). The traffic environment state consists of time to collision (TTC), time to lane Crossing (TLC), and lane color information, which are obtained from the environment in front of the vehicle, i.e., position of lanes and other vehicles. Warnings against lane-off, collision, and driver inattention are generated by fusing this vision-based information from inside and outside the vehicle. The experimental results prove that our vision-based interactive driver assistance system reduces most useless warnings.

Thin CdS films were fabricated by Langmuir deposition, self-assembly, and dip-pen nanolithography methods. Firstly, LB films of saturated arachidic acid and LS films of unsaturated 10,12-pentacosadiynoic acid were reacted with cadmium ions and exposed to H2S gas. Formation of CdS crystal was observed with Fourier transform infrared (FTIR) spectra and atomic force microscope (AFM). Secondly, mercaptohexadecanoic acid was self-assembled on Au sub- strate and was reacted with CdS colloidal particles. At pH=9.1, the density of CdS colloids immobilized on Au sub- strate was very high compared to one at pH=5.0. Finally, thin films of CdS were also prepared on silicon and Au sub- strates by cadmium chloride-coated AFM tip and successive exposure of H2S gas. Localized formation of CdS crystal was suggested with AFM and depth-profiling Auger electron microscopy (AES).

Binary self-assembled monolayers (SAMs) have been much studied due to their high applicable potential as a model of biomimetic surfaces. However, the research about miscibility of binary SAMs has not much been investigated yet. In this work, we focused on analyzing the binary SAMs composed of mercaptohexadecanoic acid (MHA)-hexadecanthiol (HDT) on gold surfaces with Cassie equation, Israelachvili equation, and FTIR spectroscopy to confirm that the binary SAMs are well mixed. As a result, MHA-HDT binary SAMs are considered miscible because the result obtained from FTIR spectra is in good agreement with that calculated by Israelachvili equation for the case that two different molecules are well mixed on the surface. Also, the adsorption of cadmium ions on binary SAMs was confirmed by the appearance of carboxylate stretching bands.

In conclusion, micro-patterned PDA vesicles were proved as a biosensor to detect a protein-protein interaction. The vesicles were conjugated with primary antibodies and immobilized on glass slides as an array form. The fluorescence level of the PDA vesicles was changed by proteinprotein interactions between primary and secondary antibodies. This experiment proves that the micro-patterned PDA vesicles are useful to detect protein level interactions and can serve as a novel substrate to develop a protein chip.

AlxGa1-xN sample with x=0.36 was epitaxially grown on sapphire by MOCVD. SAW velocity of 5420 m/s and TCF (temperature coefficient of frequency) of -51.20 ppm/°C were measured from the SAW devices fabricated on the AlxGa1-xN sample, when kh value was 0.078, at temperatures between –30 °C and 60 °C Electromechanical coupling coefficient was ranged from 1.26 % to 2.22 %. The fabricated SAW filter have shown a good device performance with insertion loss of -33.853 dB and side lobe attenuation of 20 dB.