The purpose of this study was to design capacitors and a coil, which are components of an electric circuit, for improved performance of multi-stage electromagnetic coil guns. The electromagnetic force generated in the solenoid coil is determined by the magnitude of the current, supplied from the capacitor to the solenoid coil. Since the current flowing in the solenoid coil is not constant, the variability of electromagnetic force becomes larger. Design variables such as the capacitor capacity, coil winding, and firing distance are complicatedly related and determine the coil gun firing rate together. This study sets the number of turns of the solenoid coil, capacitor capacity, and firing distance as design variables for a five-stage coil gun. The electric circuit configuration of the coil gun with the highest velocity in each firing stage, was derived through the design of experiments. The coil gun’s finite element analysis model was constructed using ANSYS Maxwell, an electromagnetic analysis program, and implemented through a transient simulation to calculate the projectile’s velocity. Additionally, a prototype was manufactured based on the derived results to conduct launch experiments, and the experimental and simulation results were compared.

From the past, productivity improvement has been a problem to be solved, and various methods have been continuously developed. Recently, the demand for electric vehicles has increased along with the domestic and international environmental policies. Researches on the electrode production facilities have been actively conducted to increase the productivity of secondary batteries. Dispensers required for bonding the separator of the secondary battery, the cathode material and the anode material are also increasing in demand. The dispensers that spray a certain amount of adhesive quickly contribute to productivity improvement. However, Piezo type, which is currently being developed and used widely, has a higher performance than some industry, and its more expensive. In this study, we design a dispenser with lower performance than the conventional piezo type and lower the unit price and analyze the results.

In this investigation, a locking mechanism was proposed for electronic products that have battery covers. The exterior design of electronic products has been advanced with diversified materials including polymers and metals. Unlike polymers such as polycarbonate, metals are not easily deformed. Therefore, products with a metallic exterior have an added button to release the battery cover, which limits the quality of the exterior design. In this study, a new design without a release button that included a miniature solenoid inside the product was proposed. The Taguchi method was used to maximize the attraction force of the solenoid while, at the same time, minimizing its dimensions.

We present a multi-sample array device based on a pneumatic system. Solenoid valves were used to control a micro valve in a pneumatic system. The use of a compressor together with a vacuum pump ensured that one outlet could supply both compression and vacuum pressure. The multi-sample array device was fabricated using conventional photolithography and PDMS casting. The device was composed of a multiplexer, sample array, and rinsing. The multiplexer could control four sample solutions injecting into the sample array chamber. Sample solution not arrayed was removed by DI-water from the rinsing inlet. To prevent trapping of microbubbles in the channel during injection of sample solution into the device, surfactant was added in PDMS solution to serve as a hydrophilic surface treatment. As a result, the device could be used as a sample array for 64 cases, using four samples and three columns of three chambers.