This paper outlines the fabrication process of the partition component, a crucial element in digital PCR. The partition component consists of thousands of micro-wells capable of holding small volumes of reagents. In this study, the partition component was created in a honeycomb structure, with hexagonally shaped micro-wells measuring 100 μm in size and spaced 20 μm apart. The fabrication process involved using photolithography, lift-off, and electroplating techniques. Photolithography and lift-off processes were employed to create a pattern of Cu metal layers in a hexagonal honeycomb arrangement on a glass substrate. Subsequently, the Cu metal-patterned substrate was used to produce pillar patterns of SU-8 with a high aspect ratio using photolithography. Finally, the gaps between the SU-8 pillar patterns were filled with nickel through electroplating, completing the partition component. The micro-wells in the partition component were designed to have an aspect ratio of 4-5; however, in this study, micro-wells with an aspect ratio of 2 and a depth of 200 μm were fabricated.

With the increasing interest in research on the development of next-generation technologies such as flexible smartphones, displays, and wearable devices, interest in the development of materials and processes for transparent electrodes constituting them is also increasing. The most widely used material for manufacturing transparent devices is indium tin oxide (ITO). However, ITO is scarce, expensive, and brittle, making it is essential to replace it with new materials. In this study, we successfully fabricated a transparent electrode by electrospinning polyvinylpyrrolidone (PVP) and copper electroless deposition on the polyimide film. Especially, this study suggests a new combined heat treatment that uses both the hot plate and the convection oven. Through the combined heat treatment, the junctions between the nanofibers overlapped removed consequently reducing contact resistance. The mechanical stability of the fabricated electrode was evaluated by using a highly repeated bending test. Also, through the tape-peeling test, we confirmed that the adhesive strength of the electrode was high. This method can be applied to various polymer-based, substrate which are vulnerable to annealing process.

Catheter tip forming is processing the tip at the distal end so that catheter can move smoothly through the geometrically complex vascular structure. This thermoforming process has a problem in that the polymer tube adheres to the outer surface of the mold. To resolve this problem, previous researchers have coated the outer surface of the mold with PTFE (Polytetrafluoroethylene), which has a low coefficient of friction. However, due to repeated use, the coating is detached and the polymer tube adheres to the mandrels again, and the mold is frequently replaced. Thus, in this study, three types of metal were electroplated on the surface of the mold in to realize the performance of the PTFE coating. To select the optimal plating material, Cr, Zn, and Ni were selected as candidate groups. Surface energy, adhesion force, and abrasion depth & volume were measured for performance comparison. As a result, Ni, which has similar surface properties to PTFE, and the best durability, was selected as the optimal material. Based on these results, we present Ni-plated mold that can replace PTFE.

In the chemical plating of the randomly loaded workpiece, it is very important to promote the agitation of plating solution and secure the space for the chemical reaction. This study investigated the possibility of chemical plating using only vibration, as well as the plating characteristics for a combination of vibration and pressurized floating. The results of the study indicate that it is possible to perform chemical plating with only vibration, and the amount of plating increases as the vibrating frequency increases. Additionally, when combined with the vibration and pressurized floating, the probability of securing a chemical reaction space and the probability of stirring become high, resulting in highly effective plating.

In the Jet-Circulating electrodeposition, selective electrodeposition is done using the local circulation of the electrolyte. The Scale of fabricated patterns using the Jet-Circulating electrodeposition is dependent on the contact area between the nozzle and the workpiece surface through the electrolyte circulation. The shape of the electrolyte meniscus determines the contact area. The factors that influence the shape of the meniscus include the electrolyte jetting parameter and the characteristics of the workpiece surface. The jet distances are analyzed based on the shape of the electrolyte meniscus and contact area which is dependent on the jetting pressure and the suction pressure. In order to investigate the effect of contact area on the workpiece surface, the surface is treated using Hexamethyldisilazane spin coating, self-assembled monolayer formation, and Neverwet ® spray coating. The contact angle and the contact area based on the surface treatment methods are analyzed. The width of the copper patterns fabricated through Jet-Circulating electrodeposition are compared. The copper pattern width of the self-assembled monolayer formation surface had reduction of 30% in comparison to the untreated surface.

Plating small sizes and quantities of workpieces requires their random loading in baskets, rather than individual loading manually. This random loading results in rubbing and collision amongst them, thereby making it impossible to conduct chemical reactions for plating, 4as the plating solution is unable to permeate to the overlapping workpiece surfaces. In this study, we developed a new plating technique under floating workpieces, by spraying high pressurized solution into a randomly loaded basket. In addition, this is accompanied by automatic optimization of the concentration through stirring of the plating solution. Experiments show that test samples were successfully floated at the optimized pressure of 50 kN/㎡. In addition, experiments in the plating parameter variation show the best plating performance at temperatures of 40℃, A and B chromate concentration at ratio = 1 : 2, an immersion time of 180 sec, and the pH value of 2.2, under optimized floated conditions.