Combinatorial Particle Patterning by Nanoxerography

In their article ( https://doi.org/10.1002/adfm.201703511 ), Bojnicic‐Kninski et al. expose the known methods used for creating, on a same substrate, patterns composed of different types of particles. This approach is called “combinatorial particle patterning.” They describe various techniques and group them depending on the used methods or driving forces that enable the directed assemblies of particles. A substantial part of the article (Part 2: Electrical Particle Patterning) referred to particle assemblies guided by electrostatic forces, i.e., electrophoretic or dielectrophoretic forces. However, this part, especially the paragraph on “Nanoxerography” (cf. 2.2 of the article) suffers from some inaccuracies that lead to partially wrong conclusions regarding combinatorial particle patterning. The goal of this comment is double: i) giving a complete and up to date definition of nanoxerography ii) reporting the results on combinatorial particle patterning using nanoxerography to correct the article inaccuracies.     

Electrically Directed On‐Chip Reversible Patterning of Two‐Dimensional Tunable Colloidal Structures

In this work, we report a versatile approach to two‐dimensional colloidal patterning based on the lateral assembly of colloidal particles by an alternating electric field (AEF). Under the AEF, the lithographically templated electrodes provide an effective way to reversibly and rapidly assemble colloidal particles into some desirable patterns. By controlling the AEF and the electrode pattern geometry, various colloidal patterns with tunable lattice spacing and even with binary lattice spacing have been formed. Particularly, we demonstrate that well‐defined linear defects can be embedded inside the colloidal crystals, whereas the unwanted existing defects can be controllably relaxed by this patterning process. This novel patterning technique is amenable to both large scale on‐chip patterning and micro‐structural control with single‐particle resolution on a time scale of seconds. Furthermore, it introduces a new class of colloidal structures with the properties that can be finely tuned, reversibly switched, or permanently fixed, opening a new way for the engineering of novel materials and devices at micro levels.     

Synthesis of Optically Complex Core–Shell Colloidal Suspensions: Pathways to Multiplexed Biological Screening

The ability to generate enormous random libraries of DNA probes via split‐and‐mix synthesis on solid supports is an important biotechnological application of colloids that has not been fully utilized to date. To discriminate between colloid‐based DNA probes each colloidal particle must be ‘encoded’ so it is distinguishable from all other particles. To this end, we have used novel particle synthesis strategies to produce large numbers of optically encoded particles suitable for DNA library synthesis. Multi‐fluorescent particles with unique and reproducible optical signatures (i.e., fluorescence and light‐scattering attributes) suitable for high‐throughput flow cytometry have been produced. In the spectroscopic study presented here, we investigated the optical characteristics of multi‐fluorescent particles that were synthesized by coating silica ‘core’ particles with up to six different fluorescent dye shells alternated with non‐fluorescent silica ‘spacer’ shells. It was observed that the diameter of the particles increased by up to 20 % as a result of the addition of twelve concentric shells and that there was a significant reduction in fluorescence emission intensities from inner shells as an increasing number of shells were deposited.     

Direct Patterning of Metal Chalcogenide Semiconductor Materials

Lithography is one of the most widely used methods for cutting‐edge research and industrial applications, mainly owing to its ability to draw patterns in the micro and even nanoscale. However, the fabrication of semiconductor micro/nanostructures via conventional electron or optical lithography technologies often requires a time‐consuming multistep process and the use of expensive facilities. Herein, a low‐cost, high‐resolution, facile, and versatile direct patterning method based on metal–organic molecular precursors is reported. The ink‐based metal–organic precursors are found to operate as negative resists, with the material exposed by different methods (electron‐beam/laser/heat/ultraviolet (UV)) to render them insoluble in the development process. This technical process can deliver metal chalcogenide semiconductors with arbitrary 2D/3D patterns with sub‐50 nm resolution. Electron beam lithography, two‐photon absorption lithography, thermal scanning probe lithography, and UV photolithography are demonstrated for the direct patterning process. Different metal chalcogenide semiconductor nanodevices, such as photoconductive selenium‐doped Sb₂S₃ nanoribbons, p‐type PbS single‐nanowire field‐effect transistors, and p‐n junction CdS/Cu₂S nanowire solar cells, are fabricated by this method. This direct patterning technique is a versatile and simple micro/nanolithography technology with considerable potential for “lab‐on‐a‐chip” preparation of semiconductor devices.     

基才一种QPSO算法的阵列天线方向图综合

方向图综合技术是智能天线中的一项关键技术。由于采用普通粒子群算法存在着易于早熟和局部寻优能力不足等缺点．为此本文提出一种基于量子位概率幅编码QPSO算法的阵列天线方向图综合技术,即在方向图综合中,QPSO算法采用量子位对粒子当前位置进行编码,用量子旋转门实现对粒子最优位置的搜索,用量子非门实现粒子位置的变异以避免早熟。实际应用表明基于量子位概率福编码QPSO的方向图综合技术是切实可行的,在多零点和低旁瓣约束情况下均可以取得良好的优化效果,具有很好的推广能力。     

微细加工技术在有机电致发光器件中的应用

有机电致发光器件是近年来出现的一种新型显示技术。为了实现高分辨率及改善器件的发光性能，多种传统的及新兴的微细加工技术已被应用到该技术中，而且针对该技术还发展了阴极隔离柱等新技术。总结了应用于有机电致发光器件的几种典型微细加工技术，并介绍了它们各自的特点及其在发光器件中的具体应用。     

Design and validation of a novel master-making process chain for organic and large area electronics on flexible substrates

This paper presents a novel process chain for fabrication of replication masters for serial manufacture. The proposed process chain is validated for serial fabrication of (large area) organic electronic devices on flexible substrates. The advantages and limitations of the component technologies in the proposed manufacturing route are discussed and their interdependencies in a process chain for producing both 2.5D and 3D nano- and micro-structures are analysed. The proposed master-making route relies on using different technologies for micro-structuring and sub-micron and nano patterning that are applied to the fabrication of Ni shims incorporating different length scale features. In particular, the capabilities of photolithography as a micro-structuring technology were combined with those of FIB machining to add sub-micron and nano-features on micro patterned fused silica templates. Then, by applying UV nanoimprint lithography such templates were validated and their nano and micro-structures were consistently replicated in one step. Finally, the feature transfer of such imprints onto Ni shims was also successfully accomplished with only minor deviations from the target dimensions.     

Selective Functionalization of Microstructured Surfaces by Laser‐Assisted Particle Transfer

Microcavity arrays represent millions of different reaction compartments to screen, for example, molecular interactions, exogenous factors for cells or enzymatic activity. A novel method is presented to selectively synthesize different compounds in arrays of microcavities with up to 1 000 000 cavities per cm². In this approach, polymer microparticles with embedded pre‐activated monomers are selectively transferred into microcavities with laser radiation. After particle patterning, heating of the particle matrix simultaneously leads to diffusion and coupling of the monomers inside each microcavity separately. This method exhibits flexibility, not only in the choice of compounds, but also in the choice of particle matrix material, which determines the chemical reaction environment. The laser‐assisted selective functionalization of microcavities can be easily combined with the intensively growing number of laser applications for patterning of molecules and cells, which is useful for the development of novel biological assays.     

燃煤飞灰的显微颗粒类型与显微结构特征

利用光学显微镜和扫描电子显微镜对不同燃煤煤种和锅炉类型电厂飞灰进行观察研究,建立了燃煤飞灰微颗粒的系统分类方案,并揭示出各类颗粒的显微结构特征,首先根据物质成分将飞灰分出硅铝质,铁质,钙质和炭粒4个组,然后根据微观形貌和内部结构分出16种显微颗粒类型。研究发现空心微珠和子母珠是飞灰中普遍存在的显微颗粒类型,不仅广泛分布于不同粒级的硅铝质颗粒中,而且常见于钙质和铁质颗粒中,发现并命名了多孔微珠这一新的显微颗粒类型;在多种颗粒中广泛分布的次级细小灰球的发现,为飞灰显微结构的成因研究提供了科学依据。     

溶液中微米级异物目标视觉检测技术

提出了一种利用机器视觉技术对溶液中μm级异物微粒进行检测并统计粒径信息的新方法。首先,建立溶液离心旋转急停后其中异物粒子的运动轨迹数学模型;然后,提取溶液视觉图像序列中每个可能目标的有效特征,通过特征匹配得到帧间若干可能目标的运动轨迹,根据异物目标与背景噪声等伪目标轨迹的差异进行甄别检测;最后,对视觉系统进行标定,确定检测到的异物目标粒径大小及各区间微粒数量。实验表明,该技术检测精度能够到达10μm,且具有较高的检测准确率。     

The Development of Yolk–Shell‐Structured Pd&ZnO@Carbon Submicroreactors with High Selectivity and Stability

Design of multicomponent yolk–shell structures is crucial for the fabrication of micro/nanoreactors for a variety of applications. This work reports the rational design and synthesis of yolk–shell‐structured submicroreactors with loaded metal nanoparticles into ZnO–microporous carbon core–shell structures. The solvothermal treatment and carbonization process of uniform zeolitic imidazolate framework‐8 (ZIF‐8)@resin polymer core–shell structures leads to the generation of yolk–shell‐structured ZnO@carbon. The synthesis conditions are optimized to track the evolution of ZIF‐8 in a confined space of resin polymer as a submicroreactor itself. It is found that nanoribbon evolution occurs via the formation of the intermediate needle‐like particles. The Pd&ZnO@carbon submicroreactor is shown to be a highly selective catalyst (selectivity >99%) for hydrogenation of phenylacetylene to phenylethylene. The excellent performance of Pd&ZnO@carbon particles is evidenced by higher conversion and selectivity than that of Pd/ZnO and Pd/C with similar Pd loading. Furthermore, Pd&ZnO@carbon submicroreactors show superior catalytic stability, and no deactivation after 25 h of reaction. The proposed strategy is promising for the design of multifunctional micro/nanoreactors or nanocontainers for construction of artificial cells.     

3D Printed Graphene-Based 3000 K Probe

High-temperature heating is ubiquitously utilized in material synthesis and manufacturing, which often features a rapid production rate due to the significantly improved kinetics. However, current technologies generally provide overall and steady-state heating, thereby limiting their applications in micro/nano-manufacturing that require selective patterning and swift heating. Herein, significantly improved control over small-scale heating is reported by utilizing 3D printed reduced-graphene-oxide (RGO) probe triggered by electrical Joule heating, which enables precise heating with high spatial (sub-millimeter scale) and temporal (milliseconds) resolutions. The block copolymer-modified aqueous-based RGO ink enabled 3D printing of high-precision structures, and a bio-inspired cellular microstructure is constructed to achieve control of the electrical conductivity and maximize structure robustness (benefit for efficient heating and operability). In particular, a thermal probe featuring a microscale tip with excellent heating capabilities (up to ≈3000 K, ultra-fast ramping rate of ≈10⁵ K s⁻¹, and durations in milliseconds) is fabricated. This thermal probe is ideal for surface patterning, as it is demonstrated for the selective synthesis of patterned metal (i.e., platinum and silver) nanoparticles on nano-carbon substrates, which is not possible by traditional steady-state heating. The material construction and heating strategy can be readily extended to a range of applications requiring precise control on high-temperature heating.     

Multifaceted and Nanobored Particle Arrays Sculpted Using Colloidal Lithography

A novel method of fabricating multifaceted and nanobored particle arrays via colloidal lithography using colloidal‐crystal layers as masks for anisotropic reactive‐ion etching (RIE) is reported. The shape of the sculpted particles is dependent on the crystal orientation relative to the etchant flow, the number of colloidal layers, the RIE conditions, and the matrix (or mask) structure in colloidal lithography. Arrays of non‐spherical particles with sculpted shapes, which to date could not otherwise be produced, are fabricated using a tilted anisotropic RIE process and the layer‐by‐layer growth of a colloidal mask. These non‐spherical particles and their ordered arrays can be used for antireflection surfaces, biosensors, and nanopatterning masks, as well as non‐spherical building blocks for novel colloidal crystals. In addition, polymeric particles with patterned holes of controlled depths obtained by the present method can be applied to the fabrication of functional composite particles.     

Complex 3D-Printed Mechanochromic Materials with Iridescent Structural Colors Based on Core–Shell Particles

A scalable protocol for design and subsequent 3D-printing of polymeric core-shell-particles is reported. The particle synthesis by emulsion polymerization in starved-feed mode is used for tailoring particle architecture and composition. Control of size, mechanical properties, and chemical functionalities allow to achieve the specific requirement profile for subsequent extrusion-based additive manufacturing. The core-shell particles consist of hard polystyrene cores and a comparably soft polyalkylacrylate-based shell. Size and monodispersity, as well as core-to-shell ratio, are determined by means of dynamic light scattering and transmission electron microscopy. Thermal and rheological properties are investigated by means of dynamic scanning calorimetry and thermogravimetric analysis as well as oscillation and capillary rheometry. During 3D-printing, the monodisperse particles self-assemble into an ordered close packed lattice structure, leading to visible reflection colors according to Bragg's law of diffraction. Distinct and angle-dependent reflection colors are recorded via UV-vis spectroscopy. As the structural color depends, inter alia, on the underlying particle sizes, resulting colors are easily tunable by adjusting the applied synthesis parameters. Under mechanical deformation, the color changes due to controlled lattice deformation, which enables mechanochromic sensing with the printed objects. They are also promising candidates for decorative ornaments, smart optical coatings, or advanced security devices.     

Fabrication of multi-dimensional colloid crystals on raised surfaces via reversal nanoimprint lithography

Fabrication of multi-dimensional colloidal crystals on raised polymer substrate has been achieved by reversal nanoimprint technique. The combine effects of the feature size of the mold, particle diameter and imprinting steps control ordering of the colloidal particles. It is shown that using ‘Reversal nanoimprint lithography’, 3D colloidal particles can be selectively patterned on soft (polymer) substrates. Reversal nanoimprint lithography offers a relatively easy, fast and versatile method for patterning of colloidal particles.     

Precisely Controlled Microsphere Design via Visible‐Light Cross‐Linking of Functional Prepolymers

A new strategy for particle synthesis is enabled by utilizing modern synthetic, polymer, and photochemical techniques to facilitate the synthesis of highly narrow–disperse multifunctional microspheres from visible‐light induced crosslinking of prepolymers in both a single and dual polymer system. The approach requires no stabilizers, bases, or initiators, and proceeds at ambient temperature to yield microspheres with a tunable size range (0.25–5 µm) in less than 4 h, depending largely on solvent composition, but also polymer concentration (2–10 mg mL^?1), ratio, and irradiation intensity (3–20 W). Critically, the visible‐light induced dimerization reaction exploited herein enables simple functional particle syntheses via a single polymer system. Underpinned by an in‐depth kinetic analysis of the particle formation as well as a detailed small molecule study, the mechanism for particle formation is also elucidated. Importantly, inherent advantages of the system are exploited for surface functionalization of residual acrylate and hydroxyl groups (generating inherently fluorescent particles).     

温度对PA、PP／SBS复合材料相结构的影响

采用磨盘型力学化学反应器制备PA－6、PP混合微粉并与SBS共混制备复合材料,用SEM、TEM研究不同温度下材料的相结构变化。结果表明,随PA、PP填充量增加,低温下,塑料相从均匀分散到聚集态形成。在高温下、塑料颗粒相熔融合并使其分散相结构发生变化直至至形成链状连续相。     

Computer Aided Tolerance Analysis and Synthesis in Micro Systems (μ-ToAST)

The large variety of the technologies and physical, chemical or biochemical effects united in micro systems requires a new generation of quality assurance. An appropriate quality management should check all conceivable influences on the product and perform a complete tolerance synthesis based on its function and with regard to manufacturing and cost optimization. In the following a new approach to function-oriented tolerance analysis and synthesis is presented.The authors have developed a computer program which assists Design Engineers in tolerance analysis and synthesis in micro technology. This contribution presents the theoretical background and the basic functionality of this software. For a better understanding a short MEMS example is shown.     

Biomolecule Arrays Using Functional Combinatorial Particle Patterning on Microchips

Biofunctionalization of surfaces in a microarray format has revolutionized biological assay applications. Here, a microarray system based on a microelectronic chip is presented that allows for a versatile combinatorial in situ molecule synthesis with very high density. Successfully demonstrating an application for peptide array synthesis, the method offers a compact approach, high combinatorial freedom, and, due to the intrinsic alignment, high and reproducible precision. Patterning the chip surface with different microparticle types which imbed different monomers, several thousand different molecule types can be simultaneously elongated layer‐by‐layer by coupling the particle imbedded monomers to the molecules growing on the chip surface. This technique has the potential for a wide application in combinatorial chemistry, as long as the desired monomeric building blocks are compatible with the chemical process.     

激光微技术的发展现状

介绍了激光微加工技术的特点,与其它微加工技术相比,激光微加工具有非接触、有选择性加工、热影响区域小、高精度与高重复率等优点,既可以通过去除方式,也可以通过材料堆积进行微加工成型。综述了几种常用的激光微加工技术及其发展趋势,微机电系统（MEMS）技术的进一步成熟,必将带动激光微技术快速发展。