Papers by Keyword: Micropattern

Abstract: The development of innovative micro components depends on the manufacturing system and process that reliable to produce the component in micro scale with good quality. In this case, using CO₂ Laser is one of microfabrication techniques to fabricate material to get micro component. In this research, experiment was performed to fabricate micropattern using engraving method by Laser CO₂ machine with several independent variables such as focus distance of nozzle Laser to workpiece (F), power of Laser (P), and velocity of nozzle Laser movement (V). The workpiece in this research was acrylic. Result of fabrication process will be identified and measured using digital microscope and surface roughness tester to get the value of workpiece quality such as surface roughness and geometrical properties as the dependent variables. The relationship of both variables will be expressed in 3D curves characteristic and mathematical models were analyzed by response surface methodology (RSM). The result of the analysis shows that the power of Laser (P) and velocity of Laser nozzle movement (V) effect is the significant variables affecting the quality of micropattern and micromold fabrications. Micromold can be fabricated using Laser CO₂ with roughness value (Ra_x) is 17,55μm, width of grove (W) is 135 μm, depth (D) is 341 μm.

Abstract: This study indicates the micropattern of molded plastic film from a mold insert using ultrasonic micro embossing. A mold insert and plastic film are heated above the glass transition temperature of plastic, and the softened plastic is flowed into the micropattern of a mold insert by applying pressure via a conventional technique. A longitudinal ultrasonic wave is added to the ultrasonic micro embossing process. The longitudinal ultrasonic wave generated by an ultrasonic system at a frequency of 35 KHz, has amplitude of 20 μm and output power of 900 W. The micropatterns of the Ni mold insert are groove-shaped and they are 2-μm wide and 200-nm deep. The Polypropylene (PP) is chosen as the replication materials. This study identifies the replication properties of the plastic film using different process parameters (working pressure, ultrasonic pressure, packing pressure, working time, ultrasonic time and packing time). Results of this study demonstrate that ultrasonic time is the most important process parameter for ultrasonic micro embossing.

Abstract: In the present study, three BMP-2 (bone morphogenetic protein-2) micropatterns were produced on polystyrene (PS) surface by microcontact printing in order to investigate the effect of protein micropattern on biomaterials surface on human chondrocytes behavior. The excellent BMP-2 micropatterns from fluorescent observation were successfully obtained. Cell adhesion and immunohistochemical assay were utilized to explore cell behavior. The results indicated that the protein micropatterns have significant influence on cell adhesion, spread, alignment and protein expression. The cells preferentially adhered on protein micropattern zones. The cells tend to spread towards micropattern direction, leading to better spread. The spread cells could excreted more type II and VI collagen than that of non-spread or poor-spread cells. The results of this paper suggested that extracellular matrix (ECM) protein micropatterns can effectively regulate human chondrocytes behavior, which may be helpful for development of new cartilage tissue.

Abstract: A novel micropatterning process for a particle assembly has been performed by using an electrophoretic deposition (EPD) method with a local electric field in a colloidal suspension generated by a three-electrode system. Monodisperse silica colloidal spheres with a diameter of 300 nm were used to fabricate micropattern of colloidal crystal. An interdigitated gold-microarray electrode with a 10 μm of width and a gold plate electrode were used as the working and the counter electrodes, respectively. After optimization of the EPD processing parameters, a micropattern was constructed from silica colloidal spheres. It had a relatively close-packed structure formed onto the interdigitated microarray electrode. This micropattern showed a characteristic optical reflectance peak due to Bragg’s law.

Abstract: Apatite micropattern was fabricated by a combination of biomimetic process and transcription of resist pattern. We optimized some fabrication conditions such as the height of resist pattern, temperature, concentrations and pH of simulated body fluid(SBF). Consequently, we successfully obtained apatite micropattern widely and homogeneously on a substrate in a short fabrication period.

Abstract: Electron beam lithography combined with electrophoretic deposition was investigated to fabricate micropatterned barium titanate (BTO) with nanostructures. High quality resist molds with micropatterns of microgrids and microdot arrays were prepared on Pt/Ti/SiO2/Si substrate by electron beam lithography. BTO nanocrystallites in a pseudo-cubic perovskite phase with an average particle size of about 10 nm were synthesized by a high-concentration sol-gel process. Well-dispersed and stable suspensions of barium titanate nanocrystallites were synthesized. Then, BTO microlines, microgrids and microdot arrays were electrophoretically deposited on micropatterned Pt/Ti/SiO2/Si substrate from these suspensions. The microstructure and properties of the BTO micropatterns were evaluated.