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Micro arc oxidation (MAO) is a prominent surface treatment to form bioceramic coating layers with beneficial physical, chemical, and biological properties on the metal substrates for biomaterial applications. In this study, MAO treatment has been performed to modify the surface characteristics of AZ31 Mg alloy to enhance the biocompatibility and corrosion resistance for implant applications by using an electrolytic mixture of Ca3(PO4)2 and C10H16N2O8 (EDTA) in the solutions. For this purpose, the calcium phosphate (Ca-P) containing thin film was successfully fabricated on the surface of the implant material. After in-vivo implantation into the rabbit bone for four weeks, the apparent growth of soft tissues and bone healing effects have been documented. The morphology, microstructure, chemical composition, and phase structures of the coating were identified by SEM, XPS, and XRD. The corrosion resistance of the coating was analyzed by polarization and salt spray test. The coatings consist of Ca-P compounds continuously have proliferation activity and show better corrosion resistance and lower roughness in comparison to mere MAO coated AZ31. The corrosion current density decreased to approximately 2.81 × 10−7 A/cm2 and roughness was reduced to 0.622 μm. Thus, based on the results, it was anticipated that the development of degradable materials and implants would be feasible using this method. This study aims to fabricate MAO coatings for orthopedic magnesium implants that can enhance bioactivity, biocompatibility, and prevent additional surgery and implant-related infections to be used in clinical applications.

Lenses are used to mount on the light-emitting diode (LED) chip to obtain the desired light distribution patterns. In this study, a lens for large viewing angle and high uniformity LED has been developed with optical grade poly methyl methacrylate (PMMA) material. TracePro software was used to design the lens while Moldex 3D software was implemented to design the mould and the mould filling phenomena. Together with micromoulding technology and Taguchi experimental method with control parameters were mould temperature (MoT), melt temperature (MT), and injection speed, a lens with optical uniformity of 87.18% and viewing angle of 128°has been developed. The experimental results showed that MoT and MT were the main factors affecting the optical quality, each with contributions greater than 50 and 30%, respectively. Though this lens is relatively small in dimension, a draft angle is needed for successful removal of the moulded PMMA lens from the mould.

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This paper presents an integrated microtechnology for the fabrication of a 3-D structure nozzle plate for a 1200-dotsper-inch (dpi) inkjet printhead. The 3-D structure nozzle plate contains a fluidic channel, nozzle chamber, and 432 conical nozzles whose taper angle is about 9 • -11 • to vertical. When the integrated 3-D structure nozzle plate is packaged onto the printhead, there is no need for alignment between the nozzle and the ink chamber, as there is when conventional production methods are employed. Therefore, misalignment of the nozzle and ink chamber is avoided, thereby reducing the cost by up to 50%, as well as greatly improving the print quality. This paper demonstrated the integration of excimer laser technology and microinjection molding to fabricate a 3-D structure nozzle plate. Excimer laser technology was used to create the high aspect ratio pattern with a tapered angle structure, and then, high-hardness Ni-Co alloy microelectroforming technology was used to achieve micromold insertion of the nozzle plate. In the microinjection molding, a variotherm control system was utilized for rapid heating to the mold temperature, which must be close to the glass temperature to ensure a good replication of the nozzle plate. The experiment resulted in the fabrication of a 3-D structure nozzle plate 2.7 mm in width and 10.8 mm in length. The total thickness was not more than 80 ± 2 μm (ink channels, nozzle chamber, and nozzle plate), and the diameter and pitch of the nozzle holes were 25 ± 2 μm for the outlet, 43 ± 2 μm for the inlet, 84 ± 2 μm in pitch, and 30 ± 2 μm for the ink channel. Using this 3-D structure nozzle plate improved the competitiveness of the inkjet printhead. We have demonstrated the manufacture of the main parts of the 3-D structure nozzle plate for a 1200-dpi printhead; the aforementioned fabrication process yields satisfactory results and can be applied to commercial production.[ 2008-0079]Index Terms-Excimer laser, Lithographie Galvanoformung Abformung (LIGA), microelectroforming, microelectromechanical systems, microinjection molding, nozzle plate.