Papers by Author: Xian Leng

Abstract: The RFID antenna is mainly fabricated by metal coil winding, copper or aluminum etching, plating, printing and so on. In this paper, the comparison of above methods is conducted and the progress of the printing method and water-based conductive ink are emphasized. Water-based conductive inks are environmental-friendly, economic, high applicability, and are widely used in screen printing, gravure, flexible printing, inkjet printing, etc. Although starts late and the technology is not very mature, the RFID antenna prepared by printing method has many advantages, such as low cost, high precision, easy operation, variety of substrates, etc. Thus the printing has great potential applications on the fabrication of RFID antenna. Furthermore, water-based conductive inks used in ink-jet printing RFID antenna will be the first choice of printed RFID antenna.

Abstract: Water-based polyurethane forms continuous and dense film after fully drying. Ink is lowly absorbed by PU film, affecting drying rate and color reproduction. In order to improve the absorption of ink on PU film, PU/nano alumina compound was prepared by adding nano alumina in PU and stirring at high speed. PU ink absorption coating was got by being coated on the substrate. The influences of different content of nano alumina to transmittance of coating and solid density of color blocks were researched. The influences of soft and hard segment of PU to image resolution and water resistance were also researched. It can be seen that transmittance reduces when content of nano alumina increases. Droplets spread less when using PU of hard segment and image resolution and solid density are also higher. At the same time, water resistance of solid blocks is much better when printed on PU of hard segment.

Abstract: In order to evaluate the practical application effect of the self-made water-based coated paper inkjet ink and to study the influence factors, their printing performance and the influence of the printed material for printing performance is studied. The drying time of coated paper ink and ordinary water-based inkjet ink are measured and compared. Drying process of ink droplet is recorded by video contact angle tester. It is found that the drying rate of the coated paper ink is higher than the ordinary ink and the diffusion of the ordinary ink is severe. The coated paper ink and ordinary ink are printed, and it is found that the former can get better image detail and color reproduction for the picture of human’s face and inanimate object. The coated paper ink can also obtain a better reproduction of tone levels. Coated paper inkjet ink is printed on different coated papers, and the color densities are measured through red, green and blue color filter. The color strength and hue error are obtained to evaluate the color characteristics on different papers. It is concluded that the coated paper inkjet ink can obtain better color on the Henglian gloss coated paper, Sunbrite gloss coated paper and SPCO matt coated paper.

Abstract: In order to acquire conductive film with high transparency, conductive polymer PEDT: PSS was mixed with some polar dopants and some surfactants. The coating fluid was acquired and coated on the PET film with different coating rods, and conductive film was gotten after drying at some temperature. The conductive mechanism of polymer after doping was introduced. Furthermore, the influenced factors of conductivity were discussed, including different dopants and surfactants as well as dried temperature. It was concluded that DMSO and EG were the best dopants, that surfactants including fluoride or silicon were suited for high conductivity. The sheet resistance of conductive film can be less than 300 Ω/□ when dried at 130 oC, at the same time the transparency at 550 nm is more than 83%. After measuring with AFM, the surface of film was sharp and the surface roughness is 7nm.