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Inorganic materials such as SiOx and SiNx are commonly used as dielectric layers in thin-film transistors (TFTs), but recent advancements in TFT devices, such as inclusion in flexible electronics, require the development of novel types of dielectric layers. In this study, CVD-deposited poly(p-xylylene) (PPx)-based polymers were evaluated as alternative dielectric layers. CVD-deposited PPx can produce thin, conformal, and pinhole-free polymer layers on various surfaces, including oxides and metals, without interfacial defects. Three types of commercial polymers were successfully deposited on various substrates and exhibited stable dielectric properties under frequency and voltage sweeps. Additionally, TFTs with PPx as a dielectric material and an oxide semiconductor exhibited excellent device performance; a mobility as high as 22.72 cm2/(V s), which is the highest value among organic gate dielectric TFTs, to the best of our knowledge. Because of the low-temperature deposition process and its unprecedented mechanical flexibility, TFTs with CVD-deposited PPx were successfully fabricated on a flexible plastic substrate, exhibiting excellent durability over 10000 bending cycles. Finally, a custom-synthesized functionalized PPx was introduced into top-gated TFTs, demonstrating the possibility for expanding this concept to a wide range of chemistries with tunable gate dielectric layers.

Recently, radioactive wastes are inevitable by-product due to rapid development and use of nuclear energy. Especially, there are large amount of liquid radioactive wastes to control nuclear fission reaction at nuclear generating station. In order to reduce total volume of solution state radioactive wastes, people have used solar evaporation without any specific instrument and it takes long time to get liquid state concentrated radioactive waste which is inefficient process. Herein we propose Janus-type membrane with different surface hydrophilicity toward efficient solar steam generation to concentrate radioactive liquid wastes. We used vapor deposition polymerization method to introduce polypyrrole (Py) and polystyrene (PS) on the top and bottom side of a cellulose paper. Py coating broadens the absorption wavelength range for enhanced photo-thermal energy conversion. Hydrophobic PS coating not only makes membrane easy to floating on water but also prevents salt accumulation during evaporation. Using this membrane, we can efficiently concentrate polluted water including Cs ion without salt accumulation on membrane, and thus no specific decrement in evaporation efficiency by time.

Polymer-based catalysts have been of special interest because of their several advantages such as easy processibility. Inorganic catalyst generally have been introduced into polymer-based media to endow catalytic activity. Surface decoration or sol–gel reaction have been performed so far, but inherent low affinity between organic/inorganic causes low efficiency in loading amount, resulting in low catalytic activity. Herein, we synthesized easily processible and highly functionalizable polyoxazoline as polymer nonwoven fiber-based catalytic supporter. Zr(OH)4 was grown on surface of fiber-web via sol–gel reaction. The Zr(OH)4 grown fiber exhibited not only excellent mechanical properties but also effective decontamination efficiency against organophosphate-based toxic agents.

Solar-to-steam generation is a powerful, intense, and efficient method to harvest solar energy. Many efforts have been devoted to the development of a durable, affordable, and easy-to-manufacture solar steam device. In this study, we use a versatile polydimethylsiloxane material to fabricate an open porous black membrane with different pore structures using a simple salt water etching process and vapor deposition polymerization of pyrrole into a matrix. The porous black membrane absorbed radiation from a broad section of the light spectrum from near-infrared to ultraviolet and retained its initial pore structures and floating ability. We found that our black membrane with a tailored pore structure and surface exhibits excellent solar-to-steam generation efficiency of up to 72% at five sun irradiation. Also, a series of analyses including density functional theory calculation was used to prove the outstanding efficiency of solar-to-steam generation.

This paper introduces an electric Hyundai Medical Exoskeleton (H-MEX). It is specially designed to enable disabled people (e.g. spinal cord injury individuals below T10, stroke patients) to walk again, according to a basic walking control strategy. H-MEX is easily assembled with mechanically/electrically block-by-block connections, and its built-in control framework provides an unique control interface. Through this interface, the H-MEX wearer can customize gait parameters (viz., the step length, step period, and default torso tilt angle). With the proposed framework, trajectories for each active joint are planned for generating propulsion (i.e., angular momentum) in double-stance gait. This facilitates stability and convenience for H-MEX wearers. A dynamic simulation was conducted on a simplified planar model that describes an average human body: the intended propulsion generation during the double-stance phase was verified to lead to angular momentum with respect to a leading stance leg, for more stable and convenient step walking. Also, the degree of propulsion was shown to be adjusted by setting kinematic percentage of intended double-stance motion. The proposed control method was evaluated with five healthy subjects on a treadmill as one of initial performance tests: kinematic data on subjects’ torsos given from basic walking at a velocity of 0.7 km/h and 1.2 km/h indicated the effectiveness of the proposed control strategy.

Steam generation from solar power using converters has attracted significant research attention in recent years as an alternative form of energy conversion from solar energy. Rationally designed photothermal converters are essential to increase the efficiency of steam generation. Here, we propose a novel colloidal type of photothermal converter based on a frustule skeleton, which is a naturally designed colloid containing through-pore structures. Several coating processes were used to provide broadband absorption, magnetic, and water-floating properties without deteriorating pore structures, through vapor deposition polymerization of polypyrrole, weak base treatment, and additional vapor deposition polymerization of polystyrene. The prepared colloidal photothermal converter showed superior efficiency for steam generation under sunlight irradiation.

N–Cl functional groups have been widely utilized for antimicrobial and detoxification purpose. However, along with the high reactivity of N–Cl moiety, long term stability of N–Cl moiety under ambient condition is of special interest for final applications. Diverse organic moieties have been developed to enhance N–Cl stability, and hydantoin N–Cl groups are generally accepted as a promising candidate. Here, N–Cl functionalized electrospun nanofibers are prepared via surface functionalization method for fabrication of catalytic nanofiber mat against chemical warfare agent. Thermoplastic polyurethane (TPU) containing abundant pandent azide moiety is firstly synthesized, and nanofiber web is prepared via electrospinning. Hydantoin functional groups that are well-known moiety to stabilize N–Cl functional groups are introduced via surface click reaction. The storage stability of N–Cl groups from surface reaction is superior than that of bulk reaction with maintaining their catalytic activity for decomposition of chemical warfare agents. In order to increase mechanical properties of nanofiber web, amount of hydantoin groups on surfaces has been controlled by blending of normal TPU with azide TPU, and blended nanofiber web maintains their inherent flexibility after hydantoin functionalization and N-chlorination. Optimized blending conditions to achieve both of high N–Cl stability and enhanced catalytic activity have been traced. Surface rich N–Cl groups show better stability with maintaining their inherent catalytic activities.

This paper introduces a novel passive type upper arm exoskeletal vest for assisting overhead jobs in industrial environment such as automotive manufacturing centers. The developed upper arm exoskeleton named as Hyundai Vest Exoskeleton (H-VEX) proposes two key mechanical structural elements: (1) an energy-storage multi-linkage mechanism dissipating spring-loaded energy according to angle-increment of a wearer’s upper arm, and (2) a poly-centric shoulder joint mechanism on the transverse plane for its proper alignment with a wearer’s shoulder joint movement. Based on the proposed mechanical structures, H-VEX has effective ergonomic properties which enable it to provide a smooth-increasing upper arm assistive torque according to increment in a wearer’s arm angle up to its target angle without impeding movements in large ranges of motion (RoM). Especially, the critical design parameters of the energy-storage multi-linkage are able to be adjusted to generate customized assistive torque responses, and additionally, this mechanism can be covered in a thin cover frame for beneficial ergonomic & cosmetic reasons. Furthermore, industrial-purposed requirements such as mechanical endurance and cost-effectiveness can be achieved taking advantages of key structures. To verify the effectiveness of H-VEX on overhead works, activation signals of electromyography (EMG) on main corresponding muscles of ten subjects carrying out overhead manipulation tasks were measured and compared with cases without wearing the exoskeletal vest. The statistical analysis on acquired EMG signal indicates that assistive torque provided by H-VEX was shown to significantly decrease activation of the shoulder-related muscles during target tasks.

The large number of patients who suffer from diseases such as gastritis, obesity, and chronic gastro-esophageal reflux disease has made the development of a new suture device using an endoscope instrument channel an important priority. This paper deals with a novel design of an endoscopic instrument that facilitates suture operations on the stomach and esophagus. Unlike a laparoscope, it is very difficult to transfer forces and moments to the end of a gastrointestinal endoscope from the outside handle dues to its extreme flexibility. The only feasible forces are pushing and pulling using wires and tubes. This new design requires only the push-pull action from the outside handle to complete suture operations. Furthermore, several stitches can be performed with a single endoscope insertion. This new endoscope suturing methodology thus significantly reduces the time for surgical operations and the pain that patients experience. The feasibility of the instrument was demonstrated through in vitro and in vivo animal experiments.

There have been active progresses in the construction of high-rise buildings since the robot and information technologies were applied to the construction industry. Although many techniques have been proposed for safe and efficient H-beam lifting and assembly, most of construction tasks are manually operated causing dangerous working environments. The objective of this study is to develop a robotic end-effector for fine H-beam alignment in high-rise building construction. The H-beam has a number of drilled holes so that bolts can go through to assemble the elements. Before the bolts are inserted to combine two H-beams, the bolt holes should be aligned with very tight tolerance. Otherwise, there is a potential for serious damage during the bolting process. In this study, an end-effector design that helps the H-beam alignment for bolting operation is proposed. Moreover, finite element analysis and computer simulations are conducted to evaluate the mechanism.

This paper deals with an automation system for steel construction based on a robotic crane. Employing an automation system for steel construction of high-rise buildings has following advantages: reducing risk factors in human operation, decreasing the construction cost, and shortening the construction period. The automated robotic crane system suggested in this paper consists of moving mechanism, robot manipulation system, and HMI (human machine interface). Moving mechanism is composed of boom, rail, and scissor-jack type manipulator. Using this mechanism, the robot manipulator can be located anywhere in CF (construction factory). The robot manipulation system is composed of a cabin and two robot arms. The cabin acts as a cockpit for the operator. The first robot arm has a bolting end-effector to assemble H-beams and the second robot arm has an alignment end-effector to align H-beams before assembling task. HMI system helps workers operate robot manipulators through a haptic device and a vision system. Also, it contains ITA (intelligent teaching agent) system that helps unskilled workers operate easily.