无颗粒型金属导电墨水的研究进展

印刷电子是一项新兴的微电子制造技术,采用喷墨方式制备电子器件在印刷电子研究中占有极为重要的地位。常用的颗粒型金属导电墨水由于颗粒本身的性质,容易出现团聚,聚沉,甚至堵塞喷嘴的现象;而以金属前驱体化合物为主要组分的无颗粒型导电墨水相比之下却表现出了极大的优势,具有制备工艺简单,稳定性高等显著特点,尤其适用于喷墨打印过程。     

中科院科研人员实现液膜嵌入式打印

正日前,中科院化学所绿色印刷重点实验室科研人员实现了墨水在另一液体内部形成"高精度嵌入式导电银线",从而有效抑制了墨滴扩散,为打印制备高集成度、高精度的三维结构电路奠定了技术基础。相关成果日前发表于《先进材料》杂志。喷墨打印技术可直接实现金属纳米粒子的图案化,是制备纳米印刷电子器件最有前景的方法之一。但受其导电墨水黏度和表面张力的影响,很难实现在     

绿色柔性喷墨打印银纳米墨水研究综述

传统导电薄膜的图形化需使用光刻工艺,涉及显影、刻蚀等多个工艺步骤,存在耗时长、器件各功能层构建复杂、成本高昂等不足。喷墨打印作为一种非真空、非接触、无掩膜、低成本、高通量、精准、便捷的桌面型沉积技术,可用于金属导线直接图形化制备,能够节约材料与时间,在柔性大面积电子器件中的应用潜力日益凸显。高性能环保导电墨水的开发是喷墨打印柔性电极制备技术最主要的瓶颈之一,其应满足无毒安全、低温烧结、高导电等需求。早期有机材料由于具有易溶液加工特性被选作可打印导体材料,如聚苯胺和PEDOT/PSS,但它们的导电性低,且化学、热、电学性质不稳定。而金墨水价格昂贵,铜墨水易氧化。相比较而言,银墨水具有高导电性、抗氧化性、稳定性以及相对合理的成本等优势,在打印电子器件领域引起了更加广泛的关注,目前已经实现商业化生产。随着电子器件在低成本、低能量消耗、高效率生产与柔性方面的需求日益增长,导电纳米银墨水的配制不仅需要考虑打印电子器件的高性能,更要满足绿色环保与低温烧结的要求。近年来,针对环保低温的高导电喷墨打印墨水制备技术,诸多研究者不仅致力于改善墨水体系,开发环保的水性墨水,还关注新型的低温烧结技术。在传统热烧结条件下,以月桂酸为分散剂、硼酸钠为还原剂的银纳米颗粒型墨水在烧结温度为125℃时电阻率为6.6μΩ·cm,而以氨水为络合剂、甲酸为还原剂的无颗粒纯溶液墨水在90℃烧结时电阻率为1.6μΩ·cm。新型烧结技术在一定程度上突破了高性能墨水喷墨打印工艺与低温烧结的限制,目前已使银电极烧结温度降低到100℃以下,电阻率低于6μΩ·cm。水性墨水的开发可减少毒性废料的产生,同时若采用多聚电解质作为分散剂,则稳定性更优于有机墨水,利于大规模生产。本文介绍了水性银纳米颗粒(SNPs)悬浮液和有机银复合物(SOC)溶液这两种水性银纳米墨水,比较了不同分散剂、络合剂、还原剂、颗粒聚集方式的墨水体系,总结了适用于柔性印刷的化学烧结、蒸气还原烧结、热水辅助烧结、光还原烧结等新型低温烧结技术。这些新型墨水体系与烧结技术有助于实现导电墨水高性能、高稳定性与柔性的统一,它们的开发和完善将极大促进柔性低温墨水和柔性打印电子器件的发展。     

微纳柔性制造与印刷电子材料

微纳加工技术主要应用在光电子和IC领域,随着国际新一轮印刷电子技术的发展,电路线宽越来越细,对印刷电子材料与应用技术提出更高要求,传统印刷术很难实现数微米以下精密电路。针对国际行业研究现状、工艺及最新进展,详细阐述微纳柔性制造技术的原理与特点。基于微纳图形化激光直写光刻技术、卷对卷纳米压印技术及其配套(微纳填充、转印和软压印)技术,以大尺寸透明导电材料的研发为例,微纳柔性制造在106.68 cm幅面上使印刷电路的线宽达到1.5μm。微纳柔性制造方法属于"加法"制造。展望了柔性制造在印刷电子材料产业发展中的前景和需求,指出微纳柔性制造与印刷材料的结合,有可能成为新一轮大尺寸柔性显示与触控、传感器件等产业发展的有力工具和推动性力量。     

铜锌锡硫纳米颗粒制备的研究进展

Cu2ZnSnS4(CZTS)具有高达104 cm-1的吸收系数,其约1.45eV的禁带宽度与太阳光谱非常匹配,且CZTS所含元素无毒、在地球上含量丰富、价格低廉,适用于辊对辊、丝网印刷等非真空的低成本制造方法,这使得CZTS太阳电池已成为最具产业化发展潜力的薄膜太阳电池之一,因而最近几年倍受关注。低成本的非真空制造方法大都采用CZTS纳米颗粒或其纳米墨水,因此高质量的CZTS纳米粉体的低成本、绿色制备成为CZTS太阳电池器件制造的重要部分。对CZTS纳米颗粒及其纳米墨水的制备方法进行了综述,分析和讨论各种CZTS粉体的制备方法工艺特点及其优缺点,并探讨其发展趋势。     

基于喷墨打印技术的柔性RC滤波器直接制备技术

为解决通过印刷电子技术制备的柔性RC滤波器中导电材料与基底间附着力差的问题,本文引入喷墨打印银离子导电墨水制备柔性RC滤波器.该方案采用经过NaOH溶液预处理后的聚酰亚胺薄膜作为电容介质层,利用DMP-2800材料喷墨打印机使银离子导电墨水在聚酰亚胺薄膜表面形成导电图案,然后对其进行化学镀铜得到柔性RC滤波器.喷墨打印银离子导电墨水制备的柔性RC滤波器成本低、制造工艺简单且易于个性化设计.实验通过百格刀测试法测得该柔性RC滤波器的附着力可达到5B级.     

无颗粒型银导电墨水的制备及其性能研究

首先以硝酸银作为银源,制备出柠檬酸银和碳酸银,然后以柠檬酸银和碳酸银为金属前驱体化合物,异丙胺为络合剂,甲醇为还原剂,另加入少量添加剂以调节粘度和表面张力等物理参数,制得无颗粒银导电墨水。该银导电墨水可以采用A4平板打印机在PET(Polyethylene terephthalate)上打印图案,并在较低的热处理温度下即可获得导电性较好的银膜。利用X射线衍射仪、扫描电子显微镜、四探针测试仪、接触角测量仪、傅里叶变换红外光谱仪、热分析仪对柠檬酸银、碳酸银、导电墨水及导电银膜进行测试表征。结果表明导电墨水经130℃热处理之后,导电银膜由均匀的纳米银颗粒组成;经130℃热处理40min后,得到的银膜的方块电阻可低至0.84Ω·□~(-1),可广泛用于电子印刷行业。     

喷墨纳米导电墨水体系研究及进展状况

文章详细介绍了纳米喷墨导电墨水体系研究，其中包括对喷墨导电墨水的组成和喷墨导电墨水的打印进行了详细说明。重点展示了国内外几个重要公司的研究情况，并对纳米喷墨导电墨水的未来发展提出了一些建议。     

纳米材料开启绿色印刷革命

正北京市重大科技成果转化和产业化项目"基于纳米材料的绿色印刷电路制备技术产业化"顺利通过专家组验收,标志着北京市纳米银导电墨水和基于纳米材料绿色印刷电路的RFID射频标签天线实现产业化,对于推动我国纳米绿色印刷电路产业发展具有重要意义。纳米材料绿色印刷电路制备技术,是将纳米导电材料直接在纸或膜表面印刷形成电路。该技术可取代传统的电路蚀刻工艺,具有工艺简单、成本低、基材丰富、易回收利用     

印刷电子用导电油墨的研究进展

印刷电子技术应用的关键在于导电油墨的研发,目前研究制备的导电油墨存在成本高、导电性差、热处理温度高等缺点,开发成本低、导电性良好、热处理温度低的导电油墨已成必然。介绍了导电油墨的应用领域和导电油墨的分类,概述了导电油墨的研究工作,并在此基础上综述了无颗粒型导电油墨的优势,展望了未来印刷电子用导电油墨的发展方向。     

导电油墨及其印刷技术的研究进展

目的 综述导电油墨及其印刷方式的研究进展,为开发价格低廉、性能稳定、导电性优良的导电油墨提供参考。方法 通过查阅文献归纳各类导电油墨的制备方式、印刷方式和应用领域,对导电油墨进行系统分类,比较各类导电油墨的性能和优缺点,并对其印刷技术进行分析,展望了导电油墨的发展前景。结果 目前关于导电油墨的研究集中在纳米银、纳米铜、石墨烯等导电填料的低温烧结油墨,主要采用丝网印刷、喷墨印刷等印刷方式,多用于制备传感器、柔性可穿戴设备等。未来的研究仍需关注如何低成本、低能耗、简单大量地制造导电油墨。结论 导电油墨的制备将与环境友好型的印刷方式相结合,向高导电性、高印刷适性发展,成为印刷电子领域的关键技术。     

Hybrid 3D Printing of Soft Electronics

Hybrid 3D printing is a new method for producing soft electronics that combines direct ink writing of conductive and dielectric elastomeric materials with automated pick‐and‐place of surface mount electronic components within an integrated additive manufacturing platform. Using this approach, insulating matrix and conductive electrode inks are directly printed in specific layouts. Passive and active electrical components are then integrated to produce the desired electronic circuitry by using an empty nozzle (in vacuum‐on mode) to pick up individual components, place them onto the substrate, and then deposit them (in vacuum‐off mode) in the desired location. The components are then interconnected via printed conductive traces to yield soft electronic devices that may find potential application in wearable electronics, soft robotics, and biomedical devices.     

液相剥离法制备石墨烯导电油墨的研究进展

目的 综述液相剥离法制备石墨烯导电油墨的研究现状，为促进石墨烯导电油墨在印刷电子领域的应用提供参考。方法 针对各种形式液相剥离制备石墨烯导电油墨的方法，分别从所使用溶剂的物理化学性能、制备流程、制得石墨烯导电油墨的性能等方面进行归纳和对比。结果 目前，液相剥离法制备石墨烯导电油墨的研究主要集中在提升石墨烯的分散性和油墨的导电性能等方面，未来需关注液相剥离过程中溶剂和助剂的选择，沿着低成本、绿色化、产业化等方向发展。     

Turning Trash into Treasure: Additive Free MXene Sediment Inks for Screen-Printed Micro-Supercapacitors

Printed functional conductive inks have triggered scalable production of smart electronics such as energy-storage devices, antennas, wearable electronics, etc. Of particular interest are highly conductive-additive-free inks devoid of costly postdeposition treatments to eliminate sacrificial components. Due to the high filler concentration required, formulation of such waste-free inks has proven quite challenging. Here, additive-free, 2D titanium carbide MXene aqueous inks with appropriate rheological properties for scalable screen printing are demonstrated. Importantly, the inks consist essentially of the sediments of unetched precursor and multilayered MXene, which are usually discarded after delamination. Screen-printed structures are presented on paper with high resolution and spatial uniformity, including micro-supercapacitors, conductive tracks, integrated circuit paths, and others. It is revealed that the delaminated nanosheets among the layered particles function as efficient conductive binders, maintaining the mechanical integrity and thus the metallic conductive network. The areal capacitance (158 mF cm⁻²) and energy density (1.64 µWh cm⁻²) of the printed micro-supercapacitors are much superior to other devices based on MXene or graphene. The ink formulation strategy of “turning trash into treasure” for screen printing highlights the potential of waste-free MXene sediment printing for scalable and sustainable production of next-generation wearable smart electronics.     

Rheological properties and screen printability of UV curable conductive ink for flexible and washable E-textiles

As a critical component for the realization of flexible electronics,multifunctional electronic textiles(etextiles)still struggle to achieve controllable printing accuracy,excellent flexibility,decent washability and simple manufacturing.The printing process of conductive ink plays an important role in manufacturing e-textiles and meanwhile is also the main source of printing defects.In this work,we report the preparation of fully flexible and washable textile-based conductive circuits with screen-printing method based on novel-developed UV-curing conductive ink that contains low temperature and fast cure features.This work systematically investigated the correlation between ink formulation,rheological properties,screen printability on fabric substrates,and the electrical properties of the e-textile made thereafter.The rheological behaviors,including the thixotropic behavior and oscillatory stress sweep of the conductive inks was found depending heavily on the polymer to diluent ratio in the formulation.Subsequently,the rheological response of the inks during screen printing showed determining influence to their printability on textile,that the proper control of ink base viscosity,recovery time and storage/loss modulus is key to ensure the uniformity of printed conductive lines and therefore the electrical conductivity of fabricated e-textiles.A formulation with 24 wt%polymer and 10.8 wt%diluent meets all these stringent requirements.The conductive lines with 1.0 mm width showed exceptionally low resistivity of 2.06×10^-5Ωcm Moreover,the conductive lines presented excellent bending tolerance,and there was no significant change in the sample electrical resistance during 10 cycles of washing and drying processes.It is believed that these novel findings and the promising results of the prepared product will provide the basic guideline to the ink formulation design and applications for screen-printing electronics textiles.     

Printable Transparent Conductive Films for Flexible Electronics

Printed electronics are an important enabling technology for the development of low‐cost, large‐area, and flexible optoelectronic devices. Transparent conductive films (TCFs) made from solution‐processable transparent conductive materials, such as metal nanoparticles/nanowires, carbon nanotubes, graphene, and conductive polymers, can simultaneously exhibit high mechanical flexibility, low cost, and better photoelectric properties compared to the commonly used sputtered indium‐tin‐oxide‐based TCFs, and are thus receiving great attention. This Review summarizes recent advances of large‐area flexible TCFs enabled by several roll‐to‐roll‐compatible printed techniques including inkjet printing, screen printing, offset printing, and gravure printing using the emerging transparent conductive materials. The preparation of TCFs including ink formulation, substrate treatment, patterning, and postprocessing, and their potential applications in solar cells, organic light‐emitting diodes, and touch panels are discussed in detail. The rational combination of a variety of printed techniques with emerging transparent conductive materials is believed to extend the opportunities for the development of printed electronics within the realm of flexible electronics and beyond.     

A New 3D Printing Strategy by Harnessing Deformation,Instability, and Fracture of Viscoelastic Inks

Direct ink writing (DIW) has demonstrated great potential as a multimaterial multifunctional fabrication method in areas as diverse as electronics, structural materials, tissue engineering, and soft robotics. During DIW, viscoelastic inks are extruded out of a 3D printer's nozzle as printed fibers, which are deposited into patterns when the nozzle moves. Hence, the resolution of printed fibers is commonly limited by the nozzle's diameter, and the printed pattern is limited by the motion paths. These limits have severely hampered innovations and applications of DIW 3D printing. Here, a new strategy to exceed the limits of DIW 3D printing by harnessing deformation, instability, and fracture of viscoelastic inks is reported. It is shown that a single nozzle can print fibers with resolution much finer than the nozzle diameter by stretching the extruded ink, and print various thickened or curved patterns with straight nozzle motions by accumulating the ink. A quantitative phase diagram is constructed to rationally select parameters for the new strategy. Further, applications including structures with tunable stiffening, 3D structures with gradient and programmable swelling properties, all printed with a single nozzle are demonstrated. The current work demonstrates that the mechanics of inks plays a critical role in developing 3D printing technology.     

Enhancing the Performance of Stretchable Conductors for E‐Textiles by Controlled Ink Permeation

Delivery of electronic functionality to the human body using e‐textiles is important for realizing the future of wearable electronics. Printing is a promising process for large scale manufacturing of e‐textile since it enables arbitrary patterns using a simple and inexpensive process. However, conductive inks printed atop of textile are vulnerable to cracking because of the deformable and porous structure of textiles. The authors develop a mechanically and electrically robust wiring by controlling ink permeation in the structure of textile. This is done by adjusting the ink's solvent. The use of butyl carbitol acetate, with its low vapor pressure and boiling point, enables deep permeation into the textile. The sheet resistance is initially 0.06 Ω sq^?1, and the resistance increasing only 70 times after stretching to 450% strain. Finally, a four‐channel electromyogram (EMG) monitoring garment is demonstrated to show the potential of a large‐scale e‐textile device for health care and sports.     

Printed UHF RFID antennas with high efficiencies using nano-particle silver ink

One of the most popular targets of conductive ink technology is to print RFID tag antennas. However, the printed RFID antennas, manufactured by conductive silver ink which is generally based on microsized silver particles, have lower conductivity and consequently lower radiation efficiency than those by conventional copper etching method. This work demonstrates nano-particle conductive silver ink that is capable of printing UHF RFID antennas with improved radiation efficiency. Compared with commercial micro-particle silver ink, the solid content of metal is much higher in the proposed nanoparticle silver ink, leading to better electrical properties. Two types of dipole antennas are printed with the proposed nano-particle as well as with commercial micro-particle inks. Also, the same antennas are fabricated by copper etching. With these conductive inks, a straight and a meandered dipole antennas are fabricated and their radiation efficiencies are measured with the Wheeler cap method. Experimental results show that the radiation efficiencies of the antennas based on nanoparticle silver ink are superior to those printed with the micro-particle silver ink, and are comparable to those of popular copper antennas.