Papers by Author: Hyung Jung Kim

Abstract: Material selection became one of the important activities for engineers in design and manufacturing processes. A selected material at the beginning of design stage affects functionality of the designed part as well as manufacturability and cost of the final product. Unfortunately there are not many accessible material databases that can be properly used for design. In this research, a web-based material database was constructed. In order to assist designers to compare different materials, two-dimensional and three-dimensional graphs for comparison of material properties were provided via the web browser. Using these graphical tools, multi-dimensional comparison was available in more intuitive manner. In addition, this web site is open to the public, and one may add new material properties to the database in order to compare the data with existing materials. To provide the database in a commercial CAD (Computer Aided Design) environment, API (Application Programming Interface) modules were developed using Web services. The web-based material database can be accessible from http://fab.snu.ac.kr/matdb.

Abstract: The rapid prototyping (RP) technology has advanced in various fields such as verification of design, and functional test. Recently, researchers have studied bio-materials to fabricate functional bio-RP parts. In this research, a nano composite deposition system (NCDS) was developed to fabricate three-dimensional functional parts for bio-applications. In the hybrid process, the material removal process by mechanical micro machining and/or the deposition process are combined. NCDS uses biocompatible or biodegradable polymer resin as matrix and various bioceramics to form bio-composite materials. To test drug release rate in vivo environment, two different types of drug delivery system (DDS) were fabricated using the bio-composite materials. 1) Container type DDS used poly(DL-lactide-co-glycolide acid)(50:50) and 5-fluorouracil as the drug composite while polycaprolactone(PCL) served as the container of the drug. 2) Scaffold type DDS formed porous microstructure with poly(DL-lactide-co-glycolide acid)(50:50) and 5-fluorouracil composite. The effect of geometry of the DDS on release rate of drug is under investigation.