기계공학부 구성원들의 많은 관심과 참여 부탁 드립니다.

▣ 주   제: Droplet jet mode near-field electrospinning (DJ-NFES) for printing nanoscale functional fibers on multi-dimensional surface

▣ 연   사: 장지영 교수

▣ 소   속: Department of Mechanical Engineering, University of Utah, USA

▣ 일   시: 2022. 5. 25.(Wed) 11:00

▣ 장   소: 제4공학관 D407호

▣ 초   청: 김종백 교수

▣ 초   록

This presentation introduces a new droplet-jet near-field electrospinning method (DJ-NFES) that overcomes the patterning limitations of the existing near-field electrospinning (NFES), the mechanical mechanics of operation, its advantages, and the possibility of various applications. Electrospinning is a very effective method for producing polymer fibers having a nano-scale diameter, which started as far-field electrospinning and has been developed into near-field electrospinning less than two decades ago. The working principle of electrospinning is based on a strong electric field formed between a conductive syringe and an electrical ground, which creates nano-sized fibers from a polymer solution. At this time, if the distance between the syringe and the ground and the corresponding voltage is simultaneously lowered, the strong electric field is maintained and the acceleration of the fiber can be lowered, enabling more precise patterning. Although such near-field electrospinning (NFES) has been variously applied to fields such as optics, bio, and sensors, the fiber speed is still fast to implement very precise micro-scale patterning, and due to strong inertia, only two-dimensional patterning was performed to date. To overcome this challenge, my group introduces a new droplet jet near field electrospinning (DJ-NFES) using nanofibers created on the surface of a spherical polymer liquid and suggests the possibility of various applications using it. DJ-NFES is formed in a very narrow space on the surface of the polymer liquid, which maintains a strong electric field for continuous fiber generation and dramatically lowers the fiber velocity. This remarkably low fiber speed (<1 mm/s) enables fiber patterning with microscale precision which was not possible until now. In addition, nanofibers created through DJ-NFES always show self-aligning properties in the direction of the strongest electric field. Using this, precise patterning is possible not only on 2-dimensional but also on 3-dimensional surfaces. The DJ-NFES sheds a light on the applicability of nanofibers to micro and nanomanufacturing processes as a new electrohydrodynamic process. When combined with various materials such as conductive polymers and biopolymers,  DJ-NFES is expected to be applicable to a wide range of fields in flexible electronics, sensors, bioscience, and optics in the future.