滚动压印装置研制与压印填充模拟

紫外滚动压印因其可以在室温下、普通大气环境中高效大面积地进行微结构制作而备受瞩目.利用自行研制的紫外滚动压印装置,实现了微结构的快速复制.实验中发现当压印速度达到某一特定值时,会不可避免地产生气泡缺陷.采用流体软件Fluent对滚动压印充填过程进行分析,来研究气泡缺陷的产生机理.结果表明,压印速度过高导致空气被堵在图形空腔内,最终形成气泡缺陷.同时,低黏度的胶液和小的接触角更利于模型填充.此研究对于获得优化的滚动压印工艺具有一定的意义.     

纳米压印技术的最新进展

总结了纳米压印技术的最新进展,其中包括压印工艺、图形赋形方法以及纳米压印技术应用三方面最新的研究成果。在压印工艺的发展方面,大面积滚轴压印的发明最具有产业化意义,它不仅解决了常规平板压印很难大面积压印成型的困难,而且整个过程是一种柔性压印过程,降低了成本,提高了压印效率,但是最小特征尺寸还有待提高;在图形赋形方法的改进中,聚合物探针阵列技术集微米和纳米成型技术于一身,压印效率高,应用前景广阔;在压印技术应用的发展中,光伏电池、电子存储设备以及传感器等为纳米压印技术的应用提供了新的领域。     

等离子体诱导铜油墨低温固化工艺及性能优化

目的 利用低温等离子体诱导铜络合物导电油墨实现在柔性基板上快速固化,制备出高导电柔性铜薄膜,并阐明油墨溶剂质量分数、预热处理时间、等离子体功率、处理时间等参数对铜膜固化结构与导电特性的影响规律。方法 通过调节油墨中的溶剂质量分数以改变油墨的铜含量及印刷铜薄膜的厚度;通过控制变量法优化低温固化工艺,并利用扫描电子显微镜、共聚焦显微镜、电阻率测量等手段表征柔性薄膜的物理特性;通过圆珠笔直写和卷对卷印刷方式测试所制备油墨与工艺在印刷柔性电子领域的适用性。结果 通过对油墨配方和等离子体处理工艺的协同优化,可以制备最薄为40 nm,最低电阻率为3.76 μΩ?cm的柔性铜薄膜。结论 等离子体处理可以实现铜络合物油墨的低温快速固化制备高性能铜薄膜,在印刷柔性电子领域展现出了巨大的应用潜力。     

卷对卷紫外压印超疏水薄膜的工艺及装置

为了实现大面积、批量化制备超疏水表面材料,文章开发了一种新型的卷对卷紫外压印技术并研制了相应装置.通过卷对卷微纳压印及快速光固化紫外固化胶将母版上的精细微米图形转移到目标柔性衬底上,无需复杂的制备工艺或苛刻的洁净加工环境,实现超疏水薄膜的快速、高效、批量化制备.文章着重讨论了应用于制备超疏水薄膜的卷对卷紫外压印工艺过程及对应各工艺而设计的机械功能模块.经工艺改进,选用改性的紫外固化胶,转印复制了20 μm×40 μm×17 μm(直径×间距×柱高)的微结构阵列,所得超疏水薄膜经氟化处理后与水接触角可达150°以上.最后,尝试使用该装置制备T型微纳结构阵列以获得疏水性更佳的表面材料.     

柔性电子卷到卷制造中导向辊牵引特性的研究进展

目的 探索柔性电子卷到卷制造过程中薄膜经过导向辊时发生皱褶、划伤和滑移等问题的原因,以期提高柔性电子薄膜的制造精度和效率。方法 总结近年来导向辊与薄膜之间夹带气体流场特性和薄膜对导向辊牵引特性的研究进展,提出进一步需要研究的要点。结果 薄膜与导向辊之间夹带气体的流场特性和薄膜对导向辊的牵引特性是柔性电子薄膜稳定传输的主要影响因素,其对提高柔性电子产品加工精度具有重要作用。结论 有效控制导向辊与薄膜之间的夹带气体流场特性和薄膜对导向辊的牵引特性有助于提高薄膜传输的精度,从而保障卷到卷制造柔性电子产品的生产质量。     

卷对卷制备微透镜阵列防伪膜

目的制备一种高线数(200线以上)的微透镜阵列防伪膜,改变国内印刷包装行业对微透镜阵列防伪膜的制备停留在200线以下的圆点微透镜阵列防伪膜的现状。方法采用卷到卷、圆压圆的制备工艺,以聚碳酸酯为原料,采用激光微刻技术制备模具,压印温度设置为139℃,转移速度设置为5m/min。结果制得一种正六角形半球状微透镜阵列防伪膜,微透镜边长为32μm,栅距为48μm,膜厚为121μm,根据微透镜阵列结构参数关系折算后光栅线数为529线。结论实现了高线数、高填充系数的微透镜阵列防伪膜的制备,提供了一种工艺简单、适于批量生产的微透镜阵列防伪膜制备方法。     

Rheological behavior of ethylene–vinyl acetate copolymer and fabrication of micropyramid arrays by roll‐to‐roll hot embossing on its thin films

Films of ethylene–vinyl acetate (EVA) copolymer with different vinyl acetate (VA) contents were adopted as flexible substrates for fabrication of micropyramid arrays by roll‐to‐roll (R2R) hot embossing at roller temperatures 40–80 °C. An empirical relationship between rheological behavior of EVA in rubbery state and demolding performance of the films was explored. Dependence of average forming height of micropyramid arrays on VA content and roller temperatures was investigated. Our study showed that both viscosity and relaxation behavior of EVA can be related to the ultimate forming height of micropyramids. The relationships can provide references for experimental research and industrial manufacture on R2R hot embossing. Retroreflection of micropyramid arrays was observed and transmittances of the two sides of embossed films were studied. Transmittances of the VA28 film embossed at 60 °C were 97.9% (the embossed side) and 41.8% (the smooth side), which showed potential applications in reflective film and antireflective film fields. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45228.     

Web Tension regulation of multispan roll-to-roll system using integrated active dancer and load cells for printed electronics applications

The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.