고분자 소재 기반 마이크로 비드의 정밀 위치 배열 공정과 응용 디바이스로의 적용 연구

Abstract

Microbeads with size ranging from hundreds of nanometers to tens of micrometers are fabricated using various polymerization techniques forming polymeric chemical bonds between the particles. They have been widely utilized in applications including display panels, and chemical, electrical, and bio sensors. In recent studies, research has been carried out on the use of microbeads in sensing applications and their chemical and electrical functionalities have been investigated for that purpose. Most of present research about micro beads focuses on the influence, measurement, and control of electrical and chemical properties of the microbeads in a micro-fluid and its own. Those studies have been limited to utilize single bead simple solutions. The research presented in this thesis is based on the technology of the system and process used for precise positioning and release of the spherical microbeads at a desired location on the target substrate. The microbeads used were produced by depositing a nano-scale gold thin film coating on a polymeric material. We can take advantage of the precise positioning of microbeads and individual bead discharge control process and employ this method in bead-based device fabrication applications. To thoroughly investigate the process of microbeads precise control and placement, 3 different types of dropping techniques were studied. One of the techniques used electrostatic force based discharge technology while the other two were microneedle based discharge and capillary based ejection techniques. The system was developed in house with customized process head and controller and it was used for continuous microbeads array printing. The position precision and droplet uniformity results obtained from the different processes used show that each process has its own pros and cons. The major technological differences among them were related to the shape and uniformity. The capillary based technique for microbeads dropping exhibited the best and most reliable results in terms of position, precision, and uniformity. Based on the excellent output, the capillary based method can be applied in device based applications like electronic paper and elastic sensing devices. The results indicate that the developed process can be viably used in the manufacturing of functional devices.