Biomedical scaffolds used in bone tissue engineering should have various properties including appropriate bioactivity, mechanical strength, and morphologically optimized pore structures. Collagen has been well known as a good biomaterial for various types of tissue regeneration, but its usage has been limited due to its low mechanical property and rapid degradation. In this work, a new hybrid scaffold consisting of polycaprolactone (PCL) and collagen is proposed for bone tissue regeneration. The PCL enhances the mechanical properties of the hybrid scaffold and controls the pore structure. Layered collagen nanofibers were used to enhance the initial cell attachment and proliferation. The results showed that the hybrid scaffold yielded better mechanical properties of pure PCL scaffold as well as enhanced biological activity than the pure PCL scaffold did. The effect of pore size on bone regeneration was investigated using two hybrid scaffolds with pore sizes of 200 ± 20 and 300 ± 27 μm. After post-seeding for 7 days, the cell proliferation with pore size, 200 ± 20 μm, was greater than that with pore size, 300 ± 27 μm, due to the high surface area of the scaffold.

The mechanical properties of biomedical scaffolds are important for applications in tissue regeneration. The dispensing system described herein, which is based on a solid free‐form fabrication technique, enables the production of design‐based scaffolds with controllable pore structures. Although current plotting systems can easily fabricate a variety of three‐dimensional scaffolds, the mechanical properties of these constructs are difficult to control because of low processing speed. To overcome this limitation, a new dispensing method, which uses a piezoelectric vibration system to improve mechanical properties, has been developed. Polycaprolactone (PCL) strands fabricated using this technique were roughly 70% stronger than normal PCL strands. To explain this increase in mechanical strength, the combined effects of the piezoelectric system and the melt‐dispensing process on the crystalline morphology and molecular orientation of PCL strands were investigated. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

This study evaluates the strength of surface treatment parts using the hard anodizing method to the aluminum alloy brake disks. In order to achieve weight reduction of vehicles, Eco-friendly cars parts of the high-quality and competitive price is to equip. Especially while pursuing parts of weight reduction, it has to maintain the strength of the surface of the brake by nature. To enhance surface strength of aluminum alloy, we use hard anodizing technology in the surface treatment.This study is resulted of 3 times greater the hardness value of the hard anodized specimen than the aluminum alloy specimen for the lightweight parts of EV brake disk