Boru Du,Jingyu Lu,Guantao Wang,Mingguang Han,Yan Gao,Sida Luo
Laser-induced graphene (LIG) is a highly promising technology for assembling thin-film electronics with miniaturized surficial patterns, although hard to guarantee both high-quality formation of raw materials and high resolution of feature size. In this study, a combined microcontact printing (μCP) and LIG protocol is creatively utilized to fabricate ultra-thin graphene films with highly ordered micro-stripe arrays. In addition to realize various patterned structures with unique scalable and stackable characteristics, PAA concentration (4–8 wt%) is systematically investigated as a critical parameter to precisely control the feature size of micro-patterns before and after the irradiation process, including line width (before: 5.37–22.44 μm, after: 4.83–22.32 μm) and average height (before: 69.81–187.39 nm, after: 5.72–48.61 nm). By further exploring a defocused multi-lasing strategy, sheet resistance of the graphene array could be optimized dramatically from 634.1 kΩ/sq to 1.9 kΩ/sq, while maintaining low ablation (45.38 % porosity) and high carbon content (84.2 wt%). Lastly, the process is demonstrated to assemble different graphene based electronic devices with miniaturized sizes, including liquid sensors with sensitivity of 2.7 % μL −1 and electrothermal heaters with temperature-ramping rate as high as 24.7 °C/s and working temperature as high as 248 °C.
Yang Xiao,Li Xiao-Ming,Kong Qing-Qiang,Liu Zhuo,Chen Jing-Peng,Jia Hui,Liu Yan-Zhen,Xie Li-Jing,Chen Cheng-Meng
Stable aqueous carbon inks, with graphene sheets (GSs) and carbon black (CB) as conductive fillers, are prepared by a simple one-pot ball-milling method. The as-prepared composite ink with 10 wt% GSs shows optimized rheological properties (viscosity and thixotropy) for screen printing. The as-printed coatings based on the above ink are uniform and dense on a polyimide substrate, and exhibit a sandwich-type conductive three dimensional network at the microscale. The resistivity of the typical composite coating is as low as 0.23±0.01 Ω cm (92±4 Ω sq −1 , 25 µm), which is 30% as that of a pure CB coating (0.77±0.01 Ω cm). It is noteworthy that the resistivity decreases to 0.18±0.01 Ω cm (72±4 Ω sq −1 , 25 µm) after a further rolling compression. The coating exhibits good mechanical flexibility, and the resistance slightly increases by 12% after 3000 bending cycles. With the CB/GSs composite coatings as a flexible conductor, fascinating luminescent bookmarks and membrane switches were fabricated, demonstrating the tremendous potential of these coatings in the commercial production of flexible electronics and devices.
危险品化学品经营许可证（带存储）