The adhesive bonding technology of carbon fiber reinforced plastics (CFRP) and aluminum alloys, is one of the lightweight joining technologies for automobiles. The strength and properties of the bonded joint, depend on the surface of the bonded part that the adhesive touches. Thus, proper surface treatment is one of the most important steps in the bonding process. The laser surface treatment of carbon fiber composites is a new form of green and environmental surface treatment technology, which can effectively clean coatings and pollutants on the surface of materials. It is also possible to improve the bonding shear strength, by changing the microstructure and roughness of the material surface through laser micro texture processing, to form a mechanically interlocked structure. In this study, a pulsed laser was used to treat the surface of CFRP. By changing the scanning line spacing during laser micro texturing, the effect of laser micro texturing on the surface morphology of CFRP and the strength of aluminum alloy bonded joints was investigated. Results show that in the laser micro texturing process, when the scanning line spacing was 0.3 mm, the maximum tensile shear strength was 14.5 MPa, approximately 200% higher than that without laser treatment.

The purpose of this study was to develop a selective patterning process with functional nanoparticles, using the selective hydrophobic treatment which can give surface energy differences. It is important to selectively pattern the nanoparticles in solution, to the desired site in a variety of fields such as transparent electrodes, displays, and bio-sensors. Selective hydrophobic treatment can reduce the additional post processes such as cleaning to remove particles unwanted position, which is a drawback of the existing solution process. Various patterns with sub-micron size that can’t be achieved with other solution processes could be fabricated by nanoimprint lithography, selective surface treatment, and a solution coating process. The transparent conductive electrode (TCE) using silver mesh patterns on the flexible substrate created from our study showed 24 Ω of sheet resistance and more than 82% transmittance. To verify the possibility of nano-patterning of various materials, quantum dot (QD) was also patterned by selectively filling. Selective surface treatment technology has significantly improved the filling process of nanoparticles into fine patterns less than 1 μm wide.

In the Jet-Circulating electrodeposition, selective electrodeposition is done using the local circulation of the electrolyte. The Scale of fabricated patterns using the Jet-Circulating electrodeposition is dependent on the contact area between the nozzle and the workpiece surface through the electrolyte circulation. The shape of the electrolyte meniscus determines the contact area. The factors that influence the shape of the meniscus include the electrolyte jetting parameter and the characteristics of the workpiece surface. The jet distances are analyzed based on the shape of the electrolyte meniscus and contact area which is dependent on the jetting pressure and the suction pressure. In order to investigate the effect of contact area on the workpiece surface, the surface is treated using Hexamethyldisilazane spin coating, self-assembled monolayer formation, and Neverwet ® spray coating. The contact angle and the contact area based on the surface treatment methods are analyzed. The width of the copper patterns fabricated through Jet-Circulating electrodeposition are compared. The copper pattern width of the self-assembled monolayer formation surface had reduction of 30% in comparison to the untreated surface.