Thian, S. C. H., Tang, Y., Fuh, J. Y. H., Wong, Y. S., Lu, L., and Loh, H. T.
International Journal of Advanced Manufacturing Technology. Jul2006, Vol. 29 Issue 9-10, p1026-1032. 7p. 11 Black and White Photographs, 3 Diagrams.
RAPID prototyping, ELECTROCHEMICAL analysis, PHOTOLITHOGRAPHY, PHOTOPOLYMERS, MACHINING, and MANUFACTURING processes
Rapid prototyping (RP) is widely used for part fabrication in the normal scale. For fabrication in micro-scale applications such as integrated circuit (IC), micro-electro-mechanical system (MEMS), methods such as surface and bulk machining are commonly used. This paper introduces a micro-fabrication technique using the RP principle, i.e., layered manufacturing, combined with mask-based micro-lithography, which is usually used in semiconductor industry. An ultraviolet (UV) excimer laser at the wavelength of 248 nm was used as the light source. A single piece of photo-mask carrying various patterns of multiple layers obtained from slicing a three dimensional (3D) micro-parts was employed for the lithography process. The preliminary results show that a certain RP photopolymer can be applied for the micro-RP, and solid layers with sharp edges can be formed from the liquid photopolymer identified. Using a unique alignment technique, a five layered gear of 1 mm in diameter has been successfully fabricated using the proposed method . [ABSTRACT FROM AUTHOR]
MECHANICAL behavior of materials, PHOTOPOLYMERS, NANOCOMPOSITE materials, TENSILE strength, and CARBON-black
Purpose - The purpose of this paper is to evaluate the mechanical properties of photopolymer/CB (carbon black) nanocomposite when applied in a visible-light rapid prototyping (RP) machine. Design/methodology/approach - The mechanical properties of the samples such as hardness and tensile strength along with thermal stability were analyzed. The curing time behavior of the photopolymer/CB nanocomposites was tested by using a rigid-body pendulum rheometer. The shrinkage property and dimensional stability were also analyzed using the technique according to ASTM D2566 and ASTM D1204, respectively. Findings - The results showed that the prototype fabricated from pristine photopolymer tended to exhibit poor mechanical properties and low thermal stability. However, after adding the photopolymer with various concentrations of nano-CB and dispersant in appropriate composition, the photopolymer/CB nanocomposite prototype not only reduced its curing time but also enhanced its mechanical properties, thermal stability and dimensional stability. Practical implications - The presented results can be used in a visible-light RP machine. Originality/value - The mechanical and thermal properties of photopolymer are improved with nano-CB additives for a RP system. [ABSTRACT FROM AUTHOR]