印刷电子用金属材料的墨水化及图案化研究进展

印刷电子是采用印刷工艺,把功能性墨水快速印制在有机或无机基材上,形成各种电子元件和线路的科学与技术。其中墨水的制备,即各种功能材料的墨水化,以及后续在软基材上的印刷成膜,即墨水的图案化,是决定印刷电子实用化发展的关键。本文主要介绍了金属材料的墨水制备及其印刷烧结技术的研究进展,讨论了印制电子带来的材料和技术的挑战及机遇,指出导电材料选择及其墨水化与图案化有机结合是未来印刷电子和材料发展的方向。     

金属纳米颗粒导电墨水的制备及其在印刷电子方面的应用

发展下一代柔性、低价和环境友好的印刷电子技术已取得大量的研究进展。印刷电子是基于印刷原理的电子制备技术,主要是将一些液体分散性好的或可溶性材料进行印刷图案化从而实现电子元器件的制备。印刷电子学涉及大量的基础学科问题,包括材料、设备、工艺与应用多方面的共性技术,但其关键技术之一在于制备环保、低成本的新型导电墨水。结合印刷电子基础与应用研究的发展现状,本文主要对金属纳米颗粒的合成及其导电墨水的制备与相关应用的最新研究进展进行了综述和讨论,并对其在传感器、薄膜晶体管(TFT)、太阳能电池及RFID等方面的最新应用进展进行了概述。     

可用于印刷电子的水性CNTs导电材料及其在印刷电子器件上的应用

印刷电子技术较传统硅基微电子技术具有大面积、柔性化与低成本的优势,具有广阔的应用前景。而印刷电子材料的制备是印刷电子技术得以蓬勃发展的关键所在。碳纳米管（CNTs）是近年来发展迅速的新型碳材料之一,可应用在透明导电薄膜、晶体管、电容器、传感器、催化剂、高强度材料等各个材料领域。本文主要介绍了采用双亲共聚物改性CNTs,制备适用于印刷电子的导电墨水及其在印刷电子器件上的应用。     

液态金属印刷电子墨水研究进展

印刷电子是一种基于印刷原理的新兴电子增材制造技术,与传统电子加工方法相比,它在大面积、柔性化、个性化、低成本制造电子等方面具有无可比拟的优势。印刷电子所用的典型导电墨水通常分为三类：碳系、高分子及金属导电墨水,然而它们在打印后仍需借助高温后处理工艺,以进一步提升打印物及墨水的电导率及运行可靠性,步骤稍显繁琐;且由于相应纳米材料及墨水的配制较为复杂,也增加了使用的成本。液态金属作为一大类新出现的电子打印墨水,近年来正日益成为重要的研究领域,这种墨水具有电导率高、制备简单、无需后处理等独特优点。为推动这一方向的研究,本文评述了国内外围绕液态金属导电墨水物理化学性质的研究进展及对应的典型打印方法,并指出了进一步发展的方向。     

功能喷墨墨水的图案化与应用

近年来,利用喷墨打印技术实现材料图案化的研究取得了重要进展,功能喷墨墨水的开发成为新型材料与器件领域的研究热点之一。本文综述了功能墨水在图案化方面的研究进展,分别围绕聚合物、无机和金属墨水在图案化方面的重要进展与应用进行了介绍,进一步展望了喷墨功能墨水在先进材料图案化、功能器件制备及3D打印技术领域的应用前景。     

TiO2掺杂调控聚苯乙烯微球折射率及胶体光子晶体结构色

胶体光子晶体由于其可调变的结构色在绿色印刷、印染等领域备受关注,而其光子带隙的宽度和位置由光子晶体的晶格参数(晶面间距,通常受胶体微球尺寸影响)和介质的折射率决定。现有人工胶体光子晶体主要基于SiO_2和高分子(如聚苯乙烯(PS)等)微球的组装制备,由于胶体微球材质种类有限,折射率调控受限,因而目前调控胶体光子晶体结构色主要靠改变胶体微球的尺寸来实现。本文首先制备高折射率(2.6)的TiO_2纳米晶,在乳液聚合制备单分散的PS(折射率1.6)微球过程中,将所制备的TiO_2纳米晶掺杂于PS微球中,通过TiO_2的掺杂量有效调控胶体微球的折射率,进而实现胶体光子晶体的结构色调控。以多色胶体光子晶体微球的水溶液为墨水,采用彩色喷墨打印技术打印了电脑设计的光子晶体彩画。本文发展的光子晶体结构色调控新技术拓展了胶体光子晶体的应用。     

光子晶体的制备及应用

光子晶体（PC）是具有光子带隙的周期性电介质结构，频率落在光子带隙中的光将被禁止传播。本文对光子晶体的能带结构、带隙的产生、制备方法及应用作了简要的介绍，重点介绍了光子晶体的制备技术及其在光电领域中的应用前景。     

多光子技术及其应用研究进展

本文对多光子技术及其应用研究进展进行了较全面综述，介绍了多光子技术的基本原理，重点评述了多光子技术在生命科学、化学、物理学和材料科学领域的应用研究进展，并对多光子技术的发展趋势作了概括。     

电喷印刷柔性传感器

柔性传感器因其在弯折、扭曲、拉伸等大变形条件下具有稳定的传感性能,所以在软体机器人、可穿戴电子和生物医疗等领域具有潜在的应用前景,受到了国内外研究者的广泛关注。与传统光刻技术相比,印刷技术制造作为增材制造,具有绿色、低成本和可大面积制造的优势,被广泛应用于柔性电子器件制备。其中,电流体动力喷墨打印(电喷印)技术因其具有多种功能材料的兼容性,被认为最有可能替代传统的光刻技术,实现柔性传感器高分辨率和跨规模制造。近年来,电喷印技术在微型化柔性传感器制造领域显示出广泛的应用潜力。本综述重点介绍了电喷印刷柔性传感器的工艺、材料和应用的最新研究进展。首先,详细介绍了电流体动力喷墨打印技术的工作原理,总结了用于电喷印的各种功能性墨水材料,然后,介绍了电喷印刷中墨水和柔性基底间表界面调控的问题。随后,综述了电喷印方法在柔性压力传感器、柔性气体传感器和柔性电化学传感器等柔性传感器制造的应用进展。最后,总结讨论了下一代电喷印刷技术在柔性传感器领域的机遇与挑战。     

墨水

所谓墨水乃是用以表现文字或记号之液体的总称,根据不同目的、而用不同性质和不同颜色之墨水,其种类很多,一般分为书写墨水、印刷用油墨及特种墨水,其中每一类中又分许多种,此处不再一一详细叙述,仅将日常生活中常用到的黑色墨汁,红色墨水及蓝黑墨水制法,原料性能及配方简述如下:     

导电油墨及其应用技术进展

印刷电子是将传统印刷工艺应用于电子产品制造的新型工艺技术,导电油墨是印刷电子关键材料之一,受到了人们的广泛关注。为了全面了解并把握导电油墨及其应用发展动态,本文结合近年来导电油墨领域文献及研究工作情况,综合分析了导电油墨的分类、构成以及其印刷工艺技术和印刷装备情况,指出导电油墨的主要发展方向在于既要开发新型功能材料（如碳纳米管、石墨烯等）在导电油墨中的应用技术,又要提高印刷成膜后导电材料间的互联性能,解决印刷电路与其它器件间的连线问题。     

MODs vs. NPs: Vying for the Future of Printed Electronics

This Minireview compares two distinct ink types, namely metal-organic decomposition (MOD) and nanoparticle (NP) formulations, for use in the printing of some of the most conductive elements: silver, copper and aluminium. Printing of highly conductive features has found purpose across a broad array of electronics and as processing times and temperatures reduce, the avenues of application expand to low-cost flexible substrates, materials for wearable devices and beyond. Printing techniques such as screen, aerosol jet and inkjet printing are scalable, solution-based processes that historically have employed NP formulations to achieve low resistivity coatings printed at high resolution. Since the turn of the century, the rise in MOD inks has vastly extended the range of potentially applicable compounds that can be printed, whilst simultaneously addressing shelf life and sintering issues. A brief introduction to the field and requirements of an ink will be presented followed by a detailed discussion of a wide array of synthetic routes to both MOD and NP inks. Unindustrialized materials will be discussed, with the challenges and outlook considered for the market leaders: silver and copper, in comparison with the emerging field of aluminium inks.     

基于原位体积加成制备导电线路的研究

本文提出一种制备导电电路的方法。以纳米铜为导电填料，以光固化树脂为连接剂，制备含铜光固化油墨，利用丝网印刷方法获得含有纳米铜的图案，利用铜与银盐间的置换反应，将铜纳米粒子图案通过原位体积加成转化为导电银图案。研究结果表明，铜图案不具有导电性，而置换反应生成的银图案具有导电性，且导电能力受铜含量、银盐浓度、光照时间、浸泡反应时间等因素影响，本实验中获得的最高电导率为1.25×10⁵ S/m，导电线路具有良好的耐弯曲、耐疲劳性能，同时兼具优异的可修复性能，为导电线路的制备提供了常温下简单有效、成本低廉的实现方法，具有重要的参考价值。     

Fabrication of Miniaturised Screen‐printed Glucose Biosensors,Using a Water‐based Ink,and the Evaluation of their Electrochemical Behaviour

This paper describes a simple, convenient approach to the fabrication of microband electrodes and microband biosensors based on screen printing technology. These devices were printed in a three‐electrode configuration on one strip; a silver/silver chloride electrode and carbon counter electrode served as reference and counter electrodes respectively. The working electrodes were fabricated by screen‐printing a water‐based carbon ink containing cobalt phthalocyanine for hydrogen peroxide detection. These were converted into a glucose microband biosensor by the addition of glucose oxidase into the carbon ink. In this paper, we discuss the fabrication and application of glucose microband electrodes for the determination of glucose in cell media. The dimensions (100–400 microns) of the microband electrodes result in radial diffusion, which results in steady state responses in the absence of stirring. The microband biosensors were investigated in cell media containing different concentrations of glucose using chronoamperometry. The device shows linearity for glucose determination in the range 0.5 mM to 2.5 mM in cell media. The screen‐printed microband biosensor design holds promise as a generic platform for future applications in cell toxicity studies.     

Acrylic-urethane/modified Rhodamine-B eco-friendly UV-curable anticounterfeiting ink

Counterfeiting is an ever-growing global problem challenging companies, governments, and customers. In recent decades, as a potential remedy, anticounterfeiting technology and information security have gained a great deal of attention from academia and industry. In this work and for the first time, Rhodamine B (RhB), an efficient and enticing fluorescent material, was modified and used as a reactive stimuli-responsive component in the formulation of an eco-friendly ink. Additionally, a UV-curable polyurethane dispersion (UCPUD) with zero volatile organic compound was synthesized and employed as the matrix for the fluorescent ink. The modified RhB and UCPUD were thoroughly characterized using Fourier-transform infrared and proton nuclear magnetic resonance analyses. Exploiting the fluorescent monomer in the ink formulations could enhance the absorption intensity (λ_max = 552 nm) of the prepared ink up to 7 with respect to its solution (λ_max = 519 nm). The printed pattern was immediately illuminated with brilliant red-pink fluorescence emission upon UV irradiation. It has been shown that the prepared fluorescent ink has potential applications in the encryption, security marking, and optical authentication of confidential cellulose substrates.     

Biosurface engineering through ink jet printing

The feasibility of thermal ink jet printing as a robust process for biosurface engineering was demonstrated. The strategy investigated was to reconstruct a commercial printer and take advantage of its colour management interface. High printing resolution was achieved by formulating bio-inks of viscosity and surface tension similar to those of commercial inks. Protein and enzyme denaturation during thermal ink jet printing was shown to be insignificant. This is because the time spent by the biomolecules in the heating zone of the printer is negligible; in addition, the air and substrate of high heat capacity absorb any residual heat from the droplet.Gradients of trophic/tropic factors can serve as driving force for cell growth or migration for tissue regeneration. Concentration gradients of proteins were printed on scaffolds to show the capability of ink jet printing. The printed proteins did not desorb upon prolonged immersion in aqueous solutions, thus allowing printed scaffold to be used under in vitro and in vivo conditions. Our group portrait was ink jet printed with a protein on paper, illustrating that complex biopatterns can be printed on large area. Finally, patterns of enzymes were ink jet printed within the detection and reaction zones of a paper diagnostic.     

Preparation of stable aqueous conductive ink with silver nanoflakes and its application on paper‐based flexible electronics

A new kind of stable aqueous conductive ink with silver nanoflakes was developed, which was also used to fabricate conductive patterns on weighing paper for flexible electronics by direct writing. Silver nanoflakes of different sizes were characterized by transmission electron microscopy. The physical properties of the conductive ink were investigated by a dynamic contact angle system, Ubbelohde viscometer, and a surface tension instrument. Conductive properties of paper‐based conductive patterns were also investigated by 4‐point probe, scanning electron microscopy, X‐ray diffraction and Uscan explorer with a 3D profilometer system. It is demonstrated how the formulation of conductive ink affects the surface morphology, microstructure conductivity, and line width of conductive patterns. It can be obtained that the paper‐based conductive patterns have low resistivity. Especially, when the sintering condition is 200 °C for 20 min, the resistivity can be down to 9.4 μΩ?cm. The application of the ink on an antenna for radio frequency identification was also studied. Copyright © 2011 John Wiley & Sons, Ltd.     

High-speed microcontact printing

We have demonstrated microcontact printing (muCP) of self-assembled monolayers in the millisecond regime. The contact formation and separation of the stamp and substrate was studied with high-speed video recordings. Using high ink concentrations and contact times as short as 1 ms, we printed monolayers of hexadecanethiol on Au, which served as a selective etch resist. High-speed muCP yields defect-free monolayers that are independent of the dimensions of the printed patterns, have high contrast between printed and unprinted areas, and enable perfect reproducibility of prints.     

Diffusion of alkanethiols in PDMS and its implications on microcontact printing (muCP)

n-Alkanethiols HS-(CH2)n-CH3 such as hexadecanethiol (HDT, n = 15), octadecanethiol (ODT, n = 17), and eicosanethiol (ECT, n = 19) have been shown to provide highly protective etch resists on microcontact-printed noble metals. As the quality of the printed pattern strongly depends on the mobility of the ink compound, we focused on understanding the diffusion behavior of HDT, ODT, and ECT in poly(dimethylsiloxane) (PDMS) stamps. We used a commercial PDMS material (Sylgard184), which is commonly used for microcontact printing (muCP), and a custom-synthesized one with a higher modulus. On the basis of linear-diffusion experiments, which maintained realistic printing conditions, we showed that the ink transport in the stamp follows Fick's law of diffusion. We then determined the diffusion coefficient by analytical and numerical modeling of the diffusion experiments. Numerical calculations were carried out with the finite-difference method applying more realistic boundary conditions (ink adsorption). Values for the diffusion coefficients of the three ink compounds in the two different PDMS materials all are on the order of (4-7) x 10(-7) cm2 s(-1). The scope and limits of the mathematical models are discussed. To demonstrate the potential of such models for microcontact printing, we simulate multiple printing cycles of an inked stamp and compare the results with experimental data.