C.M. Cheah

Characterization of SLS parts for drug delivery devices

There are many applications for rapid prototyping systems and application in the biomedical field is an important domain. Uses selective laser sintering (SLS) in this study to build porous cylindrical disc matrices for use as drug delivery devices (DDD). Studies the part‐bed temperature to ascertain its influence over the porosity of the disc matrices. They are found to have an inverse linear relationship. Also investigates the dense walls, the inherent consequences of building porous structures with the SLS, in the disc matrix as they have a direct impact on the performance of the DDD. Discusses the size constraint of the disc matrix due to the limitations of the SLS process. Also investigates the possibility of creating disc matrices of varying porosity. Experimental results demonstrate that SLS is viable in producing DDDs that have variable porosity and micro‐features.

Rapid Sheet Metal Manufacturing. Part 1: Indirect Rapid Tooling

Rapid sheet metal manufacturing (RSMM) is a closed loop process for making sheet metal products which uses advanced computer-aided techniques and computer-controlled machines to produce non-ferrous tooling directly or indirectly. The tooling would be suitable for short-run production or design evaluation of sheet metal products for which prototyping cost and lead time are greatly reduced. The key aspect of this closed-loop process is the method used to fabricate and modify the sheet metal forming tool. Various approaches are adopted in the preparation of the tooling for onward embossing on a sheet metal. The three indirect approaches use selective laser sintering (SLS), stereolithography (SLA), and high-speed computer numerical controlled (CNC) milling to build the masters from computer data models. The masters are used in the vacuum casting process to generate the non-ferrous tooling. Comparisons on quality, lead time and cost are presented.

Feasibility of tissue engineering scaffold fabrication using fused deposition modelling

The feasibility of fabricating three-dimensional (3-D) non-random porous scaffolds for Tissue Engineering (TE) purposes using the Fused Deposition Modelling (FDM) process is investigated. The structural characteristics of FDM fabricated parts, namely, 3-D pore inter-connectivity, porosity, pore size and mechanical properties were evaluated, to determine their suitability for use as TE scaffolds. The influence of FDM process parameters on these structural characteristics is presented in this paper. From the investigations, the FDM process is found to be highly capable of providing good control and reproducibility of the desired part geometry, degree of porosity and microstructure. The high influence exerted by the FDM process parameters on the part microstructure, offers the user flexibility and ease of varying the structural characteristics of built parts to meet specific structural and functional requirements of TE scaffolds.