共查询到20条相似文献,搜索用时 15 毫秒
1.
Inkjet printing (IJP) is an old but still vivifying technique for flexible and cost‐effective printing of various kinds of functional inks. Normally, IJP can only work in gaseous environments. Here, it is shown that traditional piezoelectric IJP can be performed in liquid environments with a totally different droplet dispensing and manipulating mechanism. With the same piezoelectric nozzle, the volume of the droplets printed in a carrier liquid can be thousands of times smaller than those printed in air. Therefore, this work demonstrates a working mode of traditional IJP with a highly improved resolution opening possibilities for novel applications of the IJP technique. 相似文献
2.
目的为了提高水性油墨的喷墨印刷质量,通过控制喷印工艺参数以获得良好的墨滴形态。方法分析喷印工艺控制的关键参数以及墨滴形态的表征参数,通过单因素工艺参数对墨滴形态影响的实验,分析电压、点火频率和脉冲宽度对墨滴形态各评价指标的影响程度,并运用AHP法构建墨滴形态的质量分析模型;通过多因素工艺参数组合对墨滴形态影响的正交实验,分析各工艺参数与墨滴形态参数之间的关联性,并结合质量评价模型综合评判喷印工艺参数对墨滴形态的影响。结果喷印工艺参数电压、点火频率和脉冲宽度共同影响墨滴形态的质量,脉冲宽度对其影响最大,点火频率次之,电压的影响程度最小,其权重分别为0.462,0.272,0.266。结论水性油墨喷印工艺中,通过合理地控制喷印工艺的关键参数,可以有效地提高墨滴形态质量,从而获得良好的印刷品质量。 相似文献
3.
M. Duocastella 《Thin solid films》2010,518(18):5321-5258
The formation process of sessile droplets in the laser-induced forward transfer of aqueous solutions was analyzed through time-resolved imaging. At the irradiation conditions which lead to the deposition of well-defined droplets, a cavitation bubble is generated in the laser irradiated area. Such bubble evolves into a high-speed liquid jet which propagates towards the receptor solid substrate. Once the jet impinges on the receptor substrate, liquid gently starts accumulating on the impact position, and the growth of a sessile droplet initiates. In a first stage, which only lasts a few microseconds, the forming droplet suffers a fast spreading process. Then, the jet continues feeding the forming droplet for some hundreds of microseconds, but the droplet diameter remains constant, and thus the contact angle increases. Finally, liquid feeding stops due to jet breakup, and the sessile droplet initiates a slow relaxation process in which its contact angle diminishes and its diameter increases. This deposition process results in the deposition of a single sessile droplet up to donor film-receptor substrate distances of the order of the millimeter. At higher separations, satellite droplets appear, and at even higher separations only randomly distributed small droplets are deposited. 相似文献
4.
Yang Yang Shun-Chi Chang Jayesh Bharathan Jie Liu 《Journal of Materials Science: Materials in Electronics》2000,11(2):89-96
Ink-jet printing (IJP) technology is a popular technology for desktop publishing. Since some of the conducting (or conjugated) organic molecules and polymers are solution processable, IJP becomes an ideal method for printing polymer/organic light-emitting diodes with high resolution. In this review article, we present the hybrid ink-jet printing technology (HIJP), which consists of an ink-jet printed layer in conjunction with another uniform spin-coated polymer layer, which serves as a buffer layer to seal the pin holes between the ink droplets. This HIJP technology has been successfully applied to the fabrication of polymer light-emitting logos, multicolor polymer/organic light-emitting diodes, and the built-in shadow mask for the cathode patterning for pixelated polymer LEDs. 相似文献
5.
Chenjing Yang Yao Xiao Lingjie Hu Jingyi Chen Chun-Xia Zhao Peng Zhao Jian Ruan Ziliang Wu Haifeng Yu David A Weitz Dong Chen 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(11):2207073
Elastomers generally possess low Young's modulus and high failure strain, which are widely used in soft robots and intelligent actuators. However, elastomers generally lack diverse functionalities, such as stimulated shape morphing, and a general strategy to implement these functionalities into elastomers is still challenging. Here, a microfluidic 3D droplet printing platform is developed to design composite elastomers architected with arrays of functional droplets. Functional droplets with controlled size, composition, position, and pattern are designed and implemented in the composite elastomers, imparting functional performances to the systems. The composited elastomers are sensitive to stimuli, such as solvent, temperature, and light, and are able to demonstrate multishape (bow- and S-shaped), multimode (gradual and sudden), and multistep (one- and two-step) deformations. Based on the unique properties of droplet-embedded composite elastomers, a variety of stimuli-responsive systems are developed, including designable numbers, biomimetic flowers, and soft robots, and a series of functional performances are achieved, presenting a facile platform to impart diverse functionalities into composite elastomers by microfluidic 3D droplet printing. 相似文献
6.
7.
Mojun Chen Jihyuk Yang Zhenyu Wang Zhaoyi Xu Heekwon Lee Hyeonseok Lee Zhiwen Zhou Shien‐Ping Feng Sanghyeon Lee Jaeyeon Pyo Seung Kwon Seol Dong‐Keun Ki Ji Tae Kim 《Advanced materials (Deerfield Beach, Fla.)》2019,31(44)
As competing with the established silicon technology, organic–inorganic metal halide perovskites are continually gaining ground in optoelectronics due to their excellent material properties and low‐cost production. The ability to have control over their shape, as well as composition and crystallinity, is indispensable for practical materialization. Many sophisticated nanofabrication methods have been devised to shape perovskites; however, they are still limited to in‐plane, low‐aspect‐ratio, and simple forms. This is in stark contrast with the demands of modern optoelectronics with freeform circuitry and high integration density. Here, a nanoprecision 3D printing is developed for organic–inorganic metal halide perovskites. The method is based on guiding evaporation‐induced perovskite crystallization in mid‐air using a femtoliter ink meniscus formed on a nanopipette, resulting in freestanding 3D perovskite nanostructures with a preferred crystal orientation. Stretching the ink meniscus with a pulling process enables on‐demand control of the nanostructure's diameter and hollowness, leading to an unprecedented tubular‐solid transition. With varying the pulling direction, a layer‐by‐layer stacking of perovskite nanostructures is successfully demonstrated with programmed shapes and positions, a primary step for additive manufacturing. It is expected that the method has the potential to create freeform perovskite nanostructures for customized optoelectronics. 相似文献
8.
Inkjet printing of a liquid suspension prepared by dispersing silver powders of size around 4?nm in deionized (DI) water at 30?wt% was investigated in this study. By comparing with the results of pure DI water, the effects of nanoparticles on droplet formation between the nozzle and the substrate were also studied. A bipolar pulse waveform was employed in driving the piezoelectric printhead with pulse voltage set as the primary variable of this study. Observations showed that a higher driving pulse voltage was required for the silver suspension to form droplets than DI water. The liquid column broke up at the nozzle orifice for DI water while the silver suspension broke up further away below the nozzle office. It was also observed that the droplet size of the silver suspension was smaller than that of DI water. For the silver suspension the liquid column formed was thinner and longer and the pinch-off time of the liquid column to form droplets was also longer. However, the characteristic adjustment time for droplet recombination was shorter for the silver suspension than for DI water. 相似文献
9.
目的 研究典型流体相关无量纲参数对墨滴在光滑承印物表面铺展行为的影响,确定各无量纲参数对铺展直径、铺展因子和稳定铺展时间的影响规律。方法 利用Ansys软件,建立墨滴撞击光滑壁面的数值计算模型,采用VOF模型追踪液滴形状,采用PISO算法计算压力速度耦合。引入韦伯数、雷诺数、奥内佐格数来分析墨滴撞击光滑承印物表面的铺展行为。结果 计算获得不同韦伯数、雷诺数、奥内佐格数下墨滴的最大铺展直径、最终平衡铺展直径、最大铺展因子和最终铺展时间。结论 韦伯数和雷诺数对墨滴最大铺展直径的影响较大,对最终平衡直径的影响较小。韦伯数或雷诺数越小,回缩阶段越短,越快达到平衡。韦伯数、雷诺数与最大铺展因子呈明显正相关。奥内佐格数对墨滴的最大铺展直径、最终平衡直径的影响都较小。奥内佐格数越小,回缩阶段越短,越快达到平衡,奥内佐格数与液滴最大铺展因子呈不明显的正相关性。 相似文献
10.
Depending on the spraying conditions and fluid properties, a variety of electrospray regimes exists. Here we explore the changes in ion production that accompany the transitions among the three axial spraying modes, the burst mode, the pulsating Taylor cone mode, and the cone-jet mode. Spray current oscillation and phase Doppler anemometry measurements, fast imaging of the electrified meniscus, and mass spectrometry are utilized to study the formation, size, velocity, and chemical composition of droplets produced in the three modes. High-speed images indicate that the primary droplets are produced by varicose waves and lateral kink instabilities on the liquid jet emerging from the Taylor cone, whereas secondary droplets are formed by fission. Dramatic changes in the droplet size distributions result from the various production and breakup mechanisms observed at different emitter voltages and liquid flow rates. We demonstrate that droplet fission can be facilitated by space charge effects along the liquid jet and in the plume. Compared to the other two regimes, a significantly enhanced signal-to-noise ratio, a lower degree of analyte oxidation, and milder fragmentation are observed for the cone-jet mode. 相似文献
11.
Meng Gao Minxuan Kuang Lihong Li Meijin Liu Libin Wang Yanlin Song 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(19)
Magnetosensing is a ubiquitous ability for many organism species in nature. 1D assembly, especially that arranged in single‐particle‐resolution regulation, is able to sense the direction of magnetic field depending on the enhanced dipolar interaction in the linear orientation. Inspired by the magnetosome structure in magnetotactic bacteria, a 1D assembly array of single particle resolution with controlled length and well‐behaved configuration is prepared via inkjet printing method assisted with magnetic guiding. In the fabrication process, chains in a “tip‐to‐tip” regulation with the desired number of particles are prepared in a confined tiny inkjet‐printed droplet. By adjusting the receding angle of the substrate, the assembled 1D morphology is kept/deteriorated depending on the pinning/depinning behavior during ink evaporation, which leads to the formation of well‐behaved 1D assembly/aggregated dot assembly. Owing to the high‐aspect‐ratio characteristic of the assembled structure, the as‐prepared 1D arrays can be used for magnetic field sensing with anisotropic magnetization M///M⊥ up to 6.03. 相似文献
12.
O. Schneider Ph. Epple E. Teuber B. Meyer M.P.M. Jank C. Rauh A. Delgado 《Advanced Powder Technology》2011,22(2):266-270
Ink jet printing of functional materials promises an efficient route for the manufacturing of future low cost and large-area electronics applications. The effect of capillary flow of thin liquid films, the control of droplet spreading by suitably influencing the wetting properties of surfaces, the rheology of the ink and the process design play a relevant role in improvement of ink jet printed patterns. This work presents the experimentally based numerical study of the shape of single ink jetted droplets controlled by homogeneous contact angle distributions. The dynamics of the fluid on the substrate surface is treated in the frame of the lubrication theory using the concept of a precursor film and modeling the equilibrium contact angle by a disjoining pressure. The model describes the spreading of axisymmetric droplets considering different material and process parameter configurations. It is shown that the spreading process can be modeled separately from the drying process within a certain range of contact angles. 相似文献
13.
Ink-jet printed small-molecule organic single-crystal transistors are realized by using selective surface energy modification, precise control of volume density of ink droplets on spatially patterned areas, and a co-solvent system to control solvent evaporation properties. The single-crystal formation in bottom-contact-structured transistors via direct printing is expected to permit high-density array fabrication in large-area electronics. 相似文献
14.
Pang J Stuecker JN Jiang Y Bhakta AJ Branson ED Li P Cesarano J Sutton D Calvert P Brinker CJ 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(7):982-989
This paper reports the fabrication of micro- and macropatterns of ordered mesostructured silica on arbitrary flat and curved surfaces using a facile robot-directed aerosol printing process. Starting with a homogenous solution of soluble silica, ethanol, water, and surfactant as a self-assembling ink, a columnated stream of aerosol droplets is directed to the substrate surface. For deposition at room temperature droplet coalescence on the substrates and attendant solvent evaporation result in continuous, highly ordered mesophases. The pattern profiles are varied by changing any number of printing parameters such as material deposition rate, printing speed, and aerosol-head temperature. Increasing the aerosol temperature results in a decrease of the mesostructure ordering, since faster solvent evaporation and enhanced silica condensation at higher temperatures kinetically impede the molecular assembly process. This facile technique provides powerful control of the printed materials at both the nanoscale and microscale through chemical self-assembly and robotic engineering, respectively. 相似文献
15.
16.
Miaosi Li Brendan Dyett Haitao Yu Vipul Bansal Xuehua Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(1)
A universal femtoliter surface droplet‐based platform for direct quantification of trace of hydrophobic compounds in aqueous solutions is presented. Formation and functionalization of femtoliter droplets, concentrating the analyte in the solution, are integrated into a simple fluidic chamber, taking advantage of the long‐term stability, large surface‐to‐volume ratio, and tunable chemical composition of these droplets. In situ quantification of the extracted analytes is achieved by surface‐enhanced Raman scattering (SERS) spectroscopy by nanoparticles on the functionalized droplets. Optimized extraction efficiency and SERS enhancement by tuning droplet composition enable quantitative determination of hydrophobic model compounds of rhodamine 6G, methylene blue, and malachite green with the detection limit of 10?9 to 10?11 m and a large linear range of SERS signal from 10?9 to 10?6 m of the analytes. The approach addresses the current challenges of reproducibility and the lifetime of the substrate in SERS measurements. This novel surface droplet platform combines liquid–liquid extraction and highly sensitive and reproducible SERS detection, providing a promising technique in current chemical analysis related to environment monitoring, biomedical diagnosis, and national security monitoring. 相似文献
17.
基于墨点保真度的喷墨印刷质量分析与评价 总被引:1,自引:1,他引:0
对墨点质量进行了分析,提出了以墨点保真度为评价标准的质量分析方法。介绍了基于最小覆盖圆的墨滴的理想面积,在此基础上引入了计算机图像分析法,给出了基于图像分析法的喷墨印刷质量评价方法。为喷墨印刷质量检测提出了一种简便可行的方法,此方法较传统质量分析法更为直接,适合于任意的喷墨印刷过程。 相似文献
18.
John Philip O Mondain Monval F Leal-Calderon J Bibette 《Bulletin of Materials Science》1999,22(3):313-320
In this paper, we present the results on the forces between individual colloidal liquid droplets in the presence of a weak
polyelectrolyte, poly(acrylic acid), using magnetic chaining technique. The effect of the repulsive forces have been investigated
under different experimental conditions such as polyelectrolyte concentration, adsorption time, salt concentration etc. At
a PAA concentration of 0·01% (weight), a long range repulsive force profile is observed due to the adsorption of polyelectrolyte
on the droplet, without any irreversible aggregates even at very small inter-droplet spacing. Above a concentration of 0·01
wt% of PAA, formation of irreversible chaining of droplets is observed at short inter-droplet separations due to polyelectrolyte
bridging. The onset of binding is also independently confirmed by microscopic observation. Compared to the slow adsorption
on mica surfaces, the PAA adsorption on the colloidal droplets is found to be rapid. Up to 0·1 M NaCl, the range of repulsion
and the hydrodynamic radius of the droplet is found to be increasing. 相似文献
19.
Ellis Parry Serena Bolis Steve J. Elston Alfonso A. Castrejón‐Pita Stephen M. Morris 《Advanced Engineering Materials》2018,20(3)