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.

There are various conduit structures such as arteries, veins, and airways in the human body, and they play critical roles in each tissue/organ. However, in recent years, the demand for artificial substitutes for the damaged conduit structure-based tissues and organs has significantly increased as dietary life has rapidly changed. Accordingly, various studies have been conducted, to develop a conduit structure of biocompatible polymers. In this study a 5 mm-diameter conduit structure was developed, using electrospinning process. An electrospinning setup equipped with a cylindrical-rod collector was constructed to fabricate a fibrous conduit structure, and then the impacts of process conditions on morphological and mechanical properties were investigated. Finally, it was shown that the mechanical properties of the fibrous conduit structure in circumferential direction, can be controlled by the electrospinning process conditions.

Recently, porous structures of nano/microfibers are receiving great attention because of their excellent mechanical properties, surface area to volume ratio, and permeability. In this study, thick microfiber mats were fabricated using a melt-electrospinning process in a controlled manner. A melt-electrospinning equipment including a three-axis precision motion control with pneumatic dispensing was constructed. The diameter and deposition pattern of melt-electrospun microfibers with respect to the barrel temperature and pressure were investigated. Based on identified effects of process conditions on microfiber geometry, thick microfiber mats with various properties were successfully fabricated using melt-electrospinning with snake scanning and iterative layering. Their mechanical properties and porosities were then compared and analyzed.