The roll to roll (RTR) imprint process is an integrated imprinting process where steps ranging from assignment of a function to a flexible rolled substrate to rewinding of the same substrate in a roll are performed. RTR imprint is a green, low-cost technology without limitations. In RTR imprint, it is important to manufacture the mold precisely and maintain uniform process condition. To this, process conditions have to include precision tension control, optimization of process parameters. We introduced RTR imprint to fabricate planar lightwave circuit (PLC) device for communication, by new schematic design and process optimization, we fabricated successfully optical device. The fabricated optical device showed the optical performance which was satisfied to meet international standard.

Flexible electronics have been to the fore because it is believed that flexibility can add incredible value such as light weight and mobility into the existing electronic devices and create new markets of large-area and low-cost electronics such as wearable eletronics in near future. Offset printing processes are regarded as major candidates for manufacturing the flexible electronics because they can provide the patterning resolution of micron-size effectively in large-area. In view of mechanics, the most important viewpoint in offset printing is how to achieve the synchronized movement of two contact surfaces in order to prevent slip between two contact surfaces and distortion of the blanket surface during ink transfer so that the high-resolution and good-overlay patterns can be printed. In this paper, a novel low-cost measurement method of the synchronization error using the motor control output signals is proposed and the compensation method is presented to minimize the synchronization error.

In this study, experiments were conducted for micro pattern printing to combine solution atomization process and stencil printing based on electrospray deposition. The stencil mask fabricated by etching the photosensitive glass placed below 0.3 mm distance to substrate has 100 um line width. The process parameters of electrospray deposition system for the atomization of the solution are applied voltage and supply flow rate of the solution. Meniscus angle of cone-jet was optimized by varying the supply flow rate from 0.3 ml/hr to 0.7 ml/hr. Voltage condition was verified having symmetric cone-jet angle and no pulsation at 8.5 kV applied voltage. In addition, a number of micro patterns are printed using a single 1 step process by solution atomization process. Variable line width of approximate 100 um was confirmed by changing conditions of solution atomization regardless of the pattern size of stencil mask.

We developed a compact high-precision slot-die coating machine for thin-film deposition on a flexible substrate. For smooth and precise coating, air-bearing and linear motor system were employed to minimize velocity ripple. The gap control mechanism is specially designed to have repeatability of gap between nozzle and substrate under 1 μm. Due to extremely precise gap control, the machine can coat thin-films down to 50 nm with 200 mm × 100mm size. A thin film of Ag nano-particle ink is coated for demonstration.

The digital signage display is actively researched as the next generation of large FPD. To commercialize those digital signage display, the manufacturing cost must be downed with printing method instead of conventional photolithography. Here, we demonstrate a reverse offset printed TFT electrodes for the digital signage display. For the fabricated source/drain and gate electrode, we used Ag ink, silicone blanket, Cliche and reverse offset printer. We printed uniform TFT electrode patterns with narrow line width(10 μm range) and thin thickness(nm range). In the end the printing source/drain and gate electrode are successfully achieved by optimization of experimental conditions such as Cliche surface treatment, ink coating process, delay time, off/set process and curing temperature. Also, we checked that the printing align accuracy was within 5 μm.

In this paper, silver pastes were printed on polyethylene terephthalate (PET) film using screen printing and evaluated the drying characteristics by using dry oven and NIR drying system. The printed Ag films were dried at 140 ℃ and the drying time was changed from 10 to 90 seconds. To evaluate the electrical properties of printed Ag film, sheet resistance was compared. The sheet resistance of the dried thin silver film by using NIR drying system more rapidly decreased. To clarify this phenomena, the morphology and component of the dried surfaces were measured by using the scanning electron microscope (SEM) and the energy dispersive X-ray Spectroscopy (EDX), respectively. In the EDX measurement results, the oxidation of the surface was observed in the dried thin film by using the dry oven. The NIR drying system is more applicable than conventional hot air drying to apply continuous printing system.

For depth machining in die and mold, Electrical Discharge Machining (EDM) is used generally. To make deep hole and deep shape efficiently, cemented carbide endmill for depth machining is necessary. For this purpose, cemented carbide endmill was designed using design of experiment (DOE). To improve cutting performance, endmill was coated with multilayer surface treatment, TiAlCrSiN and TiAlCrN, for higher wear resistance. In order to evaluate the endmill, Transverse Rupture Strength (TRS) test was tried for investigating the relationship between surface treatment and strength in endmill body. Scratch test was also used for measuring adhesion force of each surface treatment. To evaluate hardness of surface treatment, Atomic Force Microscope (AFM) analysis was carried out. Wear test was executed for characteristics of each surface treatment in high temperature. Consequently, TiAlCrSiN was superior to the TiAlCrN coating in case of high temperature environment such as cutting.

Circulating tumor cells (CTCs) in the bloodstream of cancer patients provide an accessible source for detection, characterization, and monitoring of nonhematological cancers. The effectiveness of the CTC-Chip for the isolation of ovarian cancer cells was demonstrated by adapting the herringbone-chip (HB-Chip). The motions of the particles on the HB chip were simulated by a unique combination of buoyant, gravitational forces, and helical flows with a computational modeling. The motions of cells are demonstrated by applying polystylene bead and ovarian cancer cells into the microfabricated HB-Chip. The experimental results from beads and cells are well accordance with the simulated ones, as previously reported by Toner group. Thus, I expect that these modeling and experimental skills will play key roles in the clinical applications on CTC isolation as well as the basic research on characterization of CTCs under flow.

The control system of human torso model and driving system of stethoscope for physical assessment trainer are developed. The detecting characteristics of circular pickup coil which is driven by square wave voltage signal with resonance frequency of LC circuits are investigated and it is confirmed that the pickup coil can detect the existence of chestpiece near the coil region. The control system of human torso model is composed of 8 channel pickup coils, Mp3 and Bluetooth module. The driving system of stethoscope is composed of chestpiece with contact switch and Bluetooth headset. The chestpiece detecting algorithm check the contact of chestpiece with human body model first and excite the pickup coil sequentially to find the location. The proposed system can be applied the physical assessment trainer.

In this research, three degree-of-freedom parallel spherical robot is developed for an artificial eyeball. The proposed system is comprised of a moving and a base plate, three prismatic actuators, and a ball joint for an angular movement of the moving plate. The vector analysis is employed to investigate the relationship between positions of the actuators and a pose of the moving plate. The required ranges for every actuators are calculated using the derived inverse kinematics in regard to the combination of two different levels for the size of the system component. Then the size of every components is determined from the analyzed trend. PI controller is employed for the position control of the moving plate. Finally the proposed system is verified using an arbitrary path of the angular movement.

A magnet gear composed of two layers of permanent magnets repeated circumferentially can transmit the power without mechanical contact. In the topology called by the magnet shutter gear known as the most competitive concept among the existing concepts, the number of pole-pairs on the high speed rotor corresponds to that of low speed rotor through electric steel set functioning as a magnetic modulator. The methodology is classified into radial type and axial type according to its magnetic path as in the motor. However, the magnetic modulator has multiple poles located separately. So, it is very complicated to assemble each module of the magnet gear mechanically and to sustain a mechanical stiffness of the modulator. The practical trouble can be solved partially through reconfiguring the modules. This paper deals with the novel magnetic shutter gear topology varying the magnetic path and its effectiveness is verified through real hardware implementation.

Ideally, it is preferable to obtain the fracture characteristics of a piping from the fracture toughness of real pipes. However, a fracture toughness test on real pipes not only incurs much expense, but is very difficult to perform. Therefore fracture toughness tests have been carried out with standard specimens instead of real pipes. But, the estimates of fracture toughness obtained from standard specimens are more conservative than those of real pipes owing to the difference in the constraint effect between real pipes and standard specimens. Therefore, we have been studied with equivalent stress gradient specimen (ESG) which is designed to behave equally compared to real pipe about stress gradient on crack tip. In this study, we will evaluate fracture characteristics of equivalent stress gradient specimen by using analytical methods and compare with those of real pipe. And finally investigate suitability of equivalent stress gradient specimen.