墨水直写、喷墨打印和激光直写技术及其在微电子器件中的应用

直写技术是一种新型微加工技术,其加工过程不需模板并可在亚微米至厘米范围实现材料加工成型。墨水直写、喷墨打印和激光直写作为最常用的直写技术,具有强大的二维、三维成型能力和优异的成型精度,可实现金属、陶瓷、聚合物、水凝胶等复杂构型的程序化构筑,被广泛应用于微电子、组织工程、微流控等领域。阐述了这3种直写技术的构型原理和材料选择,重点介绍了其在微电子器件制造中的应用,讨论了当前研究的难点和热点问题,并对其未来发展趋势进行了展望。     

基于光敏浆料的直写精细无模三维成型

配制了一种具有光敏特性的陶瓷浆料, 并用此浆料通过直写精细无模三维成型技术制备了线条直径为300μm的BaTiO3陶瓷基木堆结构. 系统地讨论了光敏浆料的配制方法、浆料直写无模成型的工作原理以及采用的烧结工艺. 制备过程中不同阶段的研究表明, 光敏浆料中的BaTiO₃纳米颗粒在烧结前未发生团聚, 从而保证挤压成型顺利进行; 烧结后样品成瓷效果好, 各向收缩均匀, 整体无变形、开裂. 该技术具有成型速度快、制造周期短、可用材料范围广等特点.     

激光直写制备金属与碳材料微纳结构与器件研究进展

激光直写技术作为一种新兴的低成本、高效、高精度的加工技术,可以适用于几乎任意自由度的二维或者三维微纳结构快速成型制备.这对光电子以及半导体微纳结构与器件的制备具有重大的意义.金属微纳结构在电子学和光子学中有着广泛的应用.本文综述了激光直写制备金属微纳结构相关研究进展.主要包括激光直写制备金、银、铜以及复合材料微纳结构与...     

三维PZT木堆结构的直写成型

配制了一种水基锆钛酸铅(PZT)陶瓷浆料, 通过直写无模成型的方法制备了直径为微米级的压电木堆结构. 流变学测量表明, 浆料属于剪切变稀型流体; 微观形貌观察和密度测量表明, 烧结后的样品已经成瓷, 且具有较高的致密度; X射线衍射(XRD)的测试结果表明, 烧结后的样品具有三方PbZr_0.58Ti_0.42O₃相; 压电常数测试结果显示该结构有较好压电性, 且压电常数d₃₃为410pC/N. 无模成型技术具有结构可设计性强, 成型速度快, 成型精度高等优点, 为压电材料和器件的设计和应用提供了新的思路.     

基于激光直写的柔性天线传感器研究

激光直写是一种高效、可规模化制备柔性电子器件的技术。本文采用激光直写技术在具有良好介电性能的聚酰亚胺薄膜上制备了一种可用于应变传感和湿度传感的柔性环形天线传感器。利用激光碳化聚酰亚胺获得的材料表面呈现多孔及堆叠片层碳结构,当施加于天线上的应变和环境湿度改变时,天线的谐振频率会发生规律变化,进而实现应变和湿度感知。制备的环形天线传感器的应变响应灵敏度为?8.943 kHz/με,湿度响应灵敏度为?6.45 MHz/RH%。采用激光直写技术制备的天线传感器可以广泛应用于结构健康监测等领域。     

微粒的激光引导直写技术

基于激光引导直写的堆积成形技术可以操纵微米尺寸的材料微粒进行组装构成微结构。本文介绍了激光引导直写技术的相关原理和研究进展,同时结合实验结果对此操作过程做了探讨,最后对相关应用前景进行了展望。     

直写3D打印陶瓷基多孔结构的研究进展

陶瓷基多孔结构既继承致密陶瓷材料耐高温、电绝缘、化学稳定的优异性能,又兼具多孔结构低密度、高比表面积、低热导率的独特优势,已被广泛应用于隔热、骨组织工程、过滤及污染物清除、电子元器件等领域。但是,陶瓷基多孔结构的传统成孔方法在宏观尺度创造复杂几何外形与微纳尺度调控孔结构形态方面仍面临巨大挑战。近几十年来,研究人员一直致力于创新陶瓷基多孔结构的加工成型方法,以直写3D打印为代表的增材制造技术成为当前研究的热点,并迅速发展出一系列成熟理论与创新方法。本文首先概述了陶瓷基多孔结构的传统成孔方法与增材制造成孔方法,进一步详细介绍了直写组装成孔工艺过程,主要包括假塑性墨水配方、固化策略、干燥及后处理,分析了传统成孔方法与直写3D打印二者的组合技术在构筑陶瓷基多级孔结构方面的可行性,总结了直写3D打印技术在制造复杂陶瓷基多孔结构领域的新观点、新进展和新发现,最后结合陶瓷基多孔结构实际应用现状对直写3D技术的未来发展与挑战进行了展望。     

利用浆料直写无模成型技术制备自支撑TiO2光降解器件

介绍了一种基于光敏特性陶瓷浆料的浆料直写无模三维成型技术制备的线条直径为270μm的TiO2木堆结构光降解器件.对光敏浆料的配制方法、浆料直写无模成型的工艺原理进行了研究;利用TEM和XRD表征光敏浆料中TiO2粉体的形貌和物相;对器件的光降解性能进行了分析与测试;利用光学显微镜和SEM对成型后的样品结构、尺寸及表面微观形貌进行了分析,并基于此分析给出了这种器件高催化效率的原因.实验结果显示,该器件具有完整的三维木堆结构,表面粗糙多孔,极大地增加了光催化的作用面积,从而使其具有较高的光降解效率.在紫外光照射10min后,初始浓度为4mg/L的亚甲基蓝溶液降解率达到76%,紫外光照射20min后,亚甲基蓝溶液降解率可达91%.     

木质素基复合材料的直写式3D打印及其功能应用

作为自然界最丰富的可再生芳香族生物质资源,木质素近年来在能源、环境、医学等领域受到广泛关注。其中,采用3D打印技术构建具有特定结构和功能的木质素基复合材料是提升木质素附加值的重要途径之一,同时可有效避免木质素化学结构复杂多变、多分散性高、刚性大等在传统材料制备过程中带来的负面影响。本文围绕木质素基复合材料的直写式3D打印,重点综述了近年来木质素基复合材料在直写式3D打印方面的研究成果与进展。首先介绍了木质素的结构特性及直写式3D打印技术;然后系统总结了木质素流变学特性与其打印性能之间的构-效关系;最后讨论了3D打印的木质素基复合材料在能源、环境等领域的应用现状及其面临的挑战,并展望了木质素基复合材料在直写式3D打印方面的发展方向。     

激光直写技术在微电极阵列制作中的应用研究

利用激光微细熔覆电子浆料(LMCEP)技术在熔融石英玻璃上初步制作了4×4微电极阵列(MEA)--目前研究细胞电生理的常用工具之一,在电极阵列背面利用微笔直写技术直接"写"上加温和热敏电阻,完成了微电极阵列、电热器件和热敏器件的集成制造.随后对电极阻抗和微加热器性能进行了测试,并在其上培养神经细胞.结果表明:激光直写导...     

3D Direct Laser Writing of Nano‐ and Microstructured Hierarchical Gecko‐Mimicking Surfaces

Applying 3D direct laser writing, artificial hierarchical gecko‐type structures are designed and fabricated down to nanometer dimensions. In this way, the elastic modulus and the length scale of the gecko's setae are very closely matched. Direct laser writing is a very flexible rapid prototyping method allowing the fabrication of arbitrary nanostructures. Since the parameters of the structures can be easily changed, this technique is perfect for design studies of dry adhesives. Measuring the adhesional forces by atomic force microscopy, the influence of several design parameters like density, aspect ratio, and tip‐shape on dry adhesion performance are systematically examined. In this way, it is revealed that hierarchy is favorable for artificial gecko‐inspired dry adhesives made of stiff materials on the nanometer scale.     

直写成型用悬浮液的设计

直写成型技术是一种新型的三维复杂结构的制备方法。本文综述了直写成型用悬浮液的研究进展: 根据直写成型悬浮液的固化特点, 将之划分为自固化悬浮液和外固化悬浮液; 分析了自固化悬浮液的流变性能要求与设计准则, 综述了典型的自固化悬浮液; 分析了外固化悬浮液的要求与固化方式, 并总结了典型的外固化悬浮液与固化方式; 探讨了直写成型用悬浮液的发展方向。     

激光直写光刻工艺技术研究

研究了利用激光直写技术制作微细图形的工艺方法，应用ＩＳＩ－２８０２型激光直写系统，通过实验，分析了激光曝光机理以及提高实用分辨力的途径。得到了激光直写系统参数与处理工艺参数之间的匹配关系，实验数据对研究制作各种掩模版、衍射光学元件以及ＡＳＩＣ电路都有应用价值。     

Gigahertz Electromagnetic Structures via Direct Ink Writing for Radio‐Frequency Oscillator and Transmitter Applications

Radio‐frequency (RF) electronics, which combine passive electromagnetic devices and active transistors to generate and process gigahertz (GHz) signals, provide a critical basis of ever‐pervasive wireless networks. While transistors are best realized by top‐down fabrication, relatively larger electromagnetic passives are within the reach of printing techniques. Here, direct writing of viscoelastic silver‐nanoparticle inks is used to produce a broad array of RF passives operating up to 45 GHz. These include lumped devices such as inductors and capacitors, and wave‐based devices such as transmission lines, their resonant networks, and antennas. Moreover, to demonstrate the utility of these printed RF passive structures in active RF electronic circuits, they are combined with discrete transistors to fabricate GHz self‐sustained oscillators and synchronized oscillator arrays that provide RF references, and wireless transmitters clocked by the oscillators. This work demonstrates the synergy of direct ink writing and RF electronics for wireless applications.     

Harnessing Photochemical Shrinkage in Direct Laser Writing for Shape Morphing of Polymer Sheets

Structures that change their shape in response to external stimuli unfold possibilities for more efficient and versatile production of 3D objects. Direct laser writing (DLW) is a technique based on two‐photon polymerization that allows the fabrication of microstructures with complex 3D geometries. Here, it is shown that polymerization shrinkage in DLW can be utilized to create structures with locally controllable residual stresses that enable programmable, self‐bending behavior. To demonstrate this concept, planar and 3D‐structured sheets are preprogrammed to evolve into bio‐inspired shapes (lotus flowers and shark skins). The fundamental mechanisms that control the self‐bending behavior are identified and tested with microscale experiments. Based on the findings, an analytical model is introduced to quantitatively predict bending curvatures of the fabricated sheets. The proposed method enables simple fabrication of objects with complex geometries and precisely controllable shape morphing potential, while drastically reducing the required fabrication times for producing 3D, hierarchical microstructures over large areas in the order of square centimeters.     

Architected Polymer Foams via Direct Bubble Writing

Polymer foams are cellular solids composed of solid and gas phases, whose mechanical, thermal, and acoustic properties are determined by the composition, volume fraction, and connectivity of both phases. A new high‐throughput additive manufacturing method, referred to as direct bubble writing, for creating polymer foams with locally programmed bubble size, volume fraction, and connectivity is reported. Direct bubble writing relies on rapid generation and patterning of liquid shell–gas core droplets produced using a core–shell nozzle. The printed polymer foams are able to retain their overall shape, since the outer shell of these bubble droplets consist of a low‐viscosity monomer that is rapidly polymerized during the printing process. The transition between open‐ and closed‐cell foams is independently controlled by the gas used, while the foam can be tailored on‐the‐fly by adjusting the gas pressure used to produce the bubble droplets. As exemplars, homogeneous and graded polymer foams in several motifs, including 3D lattices, shells, and out‐of‐plane pillars are fabricated. Conductive composite foams with controlled stiffness for use as soft pressure sensors are also produced.     

Three‐Dimensional Printing of Multifunctional Nanocomposites: Manufacturing Techniques and Applications

The integration of nanotechnology into three‐dimensional printing (3DP) offers huge potential and opportunities for the manufacturing of 3D engineered materials exhibiting optimized properties and multifunctionality. The literature relating to different 3DP techniques used to fabricate 3D structures at the macro‐ and microscale made of nanocomposite materials is reviewed here. The current state‐of‐the‐art fabrication methods, their main characteristics (e.g., resolutions, advantages, limitations), the process parameters, and materials requirements are discussed. A comprehensive review is carried out on the use of metal‐ and carbon‐based nanomaterials incorporated into polymers or hydrogels for the manufacturing of 3D structures, mostly at the microscale, using different 3D‐printing techniques. Several methods, including but not limited to micro‐stereolithography, extrusion‐based direct‐write technologies, inkjet‐printing techniques, and popular powder‐bed technology, are discussed. Various examples of 3D nanocomposite macro‐ and microstructures manufactured using different 3D‐printing technologies for a wide range of domains such as microelectromechanical systems (MEMS), lab‐on‐a‐chip, microfluidics, engineered materials and composites, microelectronics, tissue engineering, and biosystems are reviewed. Parallel advances on materials and techniques are still required in order to employ the full potential of 3D printing of multifunctional nanocomposites.     

锑化物二类超晶格热电材料:能带结构、热电性能、制备与测试

热电器件由于结构简单、可靠性好、无污染等优点,在微电子、能源等领域具有广泛的应用。探索具有高热电优值(ZT)的新材料是近些年来的研究热点。超晶格材料由于独特的量子限制效应和声子界面散射,ZT值比块体材料大幅度提高。而锑化物二类超晶格与传统超晶格不同,其禁带呈错开状,由此又可以带来热电性能新的变化。阐述了锑化物二类超晶格的能带结构以及能够获得高ZT值的优势,介绍了其热电机理和研究进展,以及当前该类超晶格的制备工艺和测试方法。     

Direct laser writing of three-dimensional photonic-crystal templates for telecommunications

The past decade has witnessed intensive research efforts related to the design and fabrication of photonic crystals. These periodically structured dielectric materials can represent the optical analogue of semiconductor crystals, and provide a novel platform for the realization of integrated photonics. Despite intensive efforts, inexpensive fabrication techniques for large-scale three-dimensional photonic crystals of high enough quality, with photonic bandgaps at near-infrared frequencies, and built-in functional elements for telecommunication applications, have been elusive. Direct laser writing by multiphoton polymerization of a photoresist has emerged as a technique for the rapid, cheap and flexible fabrication of nanostructures for photonics. In 1999, so-called layer-by-layer or woodpile photonic crystals were fabricated with a fundamental stop band at 3.9 microm wavelength. In 2002, a corresponding 1.9 microm was achieved, but the important face-centred-cubic (f.c.c.) symmetry was abandoned. Importantly, fundamental stop bands or photonic bandgaps at telecommunication wavelengths have not been demonstrated. In this letter, we report the fabrication--through direct laser writing--and detailed characterization of high-quality large-scale f.c.c. layer-by-layer structures, with fundamental stop bands ranging from 1.3 to 1.7 microm.