Polymers in conventional and alternative lithography for the fabrication of nanostructures

This review provides a survey of lithography techniques and the resist materials employed with these techniques. The first part focuses on the conventional lithography methods used to fabricate complex micro- and nano-structured surfaces. In the second part, emphasis is placed on patterning with unconventional lithography techniques such as printing, molding, and embossing, and on their development into viable, high-resolution patterning technologies.     

Green Precursors and Soft Templating for Printing Porous Carbon-Based Micro-supercapacitors

A combination of soft lithographic printing and soft templating has been used to fabricate high-resolution interdigitated micro-supercapacitors (MSC). Surfactant-assisted self-assembly produces high surface area ordered mesoporous carbons (490 m² g⁻¹). For the first time, such precursors have been printed by nano-imprint lithography as microdevices with a line width of only 250 nm and a spacing of only 1 μm. The devices are crack-free with low specific resistance (1.2×10⁻⁵ Ωm) and show good device capacitance up to 0.21 F cm⁻³.     

Cover Picture: Spectroscopic Tracking of Molecular Transport Junctions Generated by Using Click Chemistry (Angew. Chem. Int. Ed. 28/2009)

The in situ generation of molecules that bridge nanogaps generated by on‐wire lithography is achieved by using click chemistry. C. A. Mirkin, M. A. Ratner, and co‐workers show in their Communication on page 5178 ff. that these molecular junctions give high yields, and they describe how this strategy can be generalized to incorporate diverse molecular architectures within the nanogaps. Tracking of the molecular assembly process within the nanogaps is allowed by their strong electromagnetic field.

     

Complex three-dimensional microparticles from microfluidic lithography

Complex 3D microparticle, as an emerging and attractive field, has attracted more and more attention due to its versatile morphologies and broad range of applications. In this review, we provide an overall recent progress in 3D microparticles fabricated by microfluidic lithography. This review will focus on the synthesis mechanisms, synthesis process, the resultant 3D microparticles, and their applications. Finally, we will look into the future trends in complex 3D microparticles. This review will be beneficial for researchers in numerous fields, including functional materials, sensors, encryption, and biomedical engineering.     

纳米压印抗蚀剂研究进展

纳米压印是最有希望的下一代纳米成像技术之一.基于其机械压印原理,纳米压印技术可以实现的图形分辨率超越了在别的传统技术中由光衍射或粒子束散射造成的局限.本文介绍纳米压印技术的基本原理,回顾了近期纳米压印抗蚀剂的研究进展.对影响抗蚀剂性能的主要因素进行讨论,包括玻璃化转化温度/热稳定性、粘度/平均分子量、抗蚀性能等.分别介绍了热压印和紫外压印的常见抗蚀剂材料,这些抗蚀剂的主要部分包括聚甲基丙烯酸甲酯(PM-MA)、有机硅改性的聚(甲基)丙烯酸酯、聚酰胺酯、聚二甲基硅烷、聚乙烯基醚化合物、环氧树脂等,并给出这些抗蚀剂体系的优、缺点.本文还介绍了纳米压印抗蚀剂面临的主要问题,对纳米压印技术的优势和问题作了小结.     

Hydrogel with Orthogonal Reactive Units: 2D and 3D Cross‐Linking Modulation

In this work, an engineered hydrogel system with a 2D and 3D tunable cross‐linking degree is presented. A precise chemical design by the introduction of cross‐linkable units, having reaction orthogonality, allows to control the network formation both in time and space and to selectively alter the hydrogel physical properties. Hydrogel chemistry has been tailored in order to produce spatially controlled stiffness changes and drive cell morphology through mechanical cues. Elastic modulus rises by more than double after photocross‐linking, as shown by atomic force microscopy measurements. Biological response is also analyzed and stiffness‐dependent cell spreading and proliferation are verified. Different pattern geometries are successfully realized by UV lithography, allowing 2D cross‐linking modulation. Furthermore, 3D mechanical tuning at micro‐ and submicrometer scale by two‐photon polymerization makes this system a biologically relevant matrix to study cell functions and tissue development.

     

On‐Tip Photo‐Modulated Molecular Printing

The concept of using cantilever‐free scanning probe arrays as structures that can modulate nanoscale ink flow and composition with light is introduced and evaluated. By utilizing polymer pen arrays with an opaque gold layer surrounding the base of the transparent polymer pyramids, we show that inks with photopolymerizable or isomerizable constituents can be used in conjunction with light channelled through the pyramids to control ink viscosity or composition in a dynamic manner. This on‐tip photo‐modulated molecular printing provides novel chemically and mechanically controlled approaches to regulating ink transport and composition in real time and could be useful not only for rapidly adjusting feature size but also for studying processes including photoreactions and mass transport at the nanoscale, self‐assembly, and cell–material interactions.     

Mapping Acid‐Catalyzed Deprotection in Thin Polymer Films: Fluorescence Imaging Using Prefluorescent 7‐Hydroxycoumarin Probes

Summary: Fluorescent images that illustrate acid‐catalyzed tert‐butoxycarbonyl (tBoc) deprotection patterns in polymer films were obtained using fluorescent sensors based on 7‐hydroxycoumarin dyes. Three commercial 7‐hydroxycoumarins, which are highly fluorescent, become practically nonemissive upon protection of the 7‐hydroxyl position with tBoc. In thin polymer films, the protected “prefluorescent” probes can return to their deprotected, fluorescent states by reaction with catalytic amounts of photogenerated acid and mild heating.

Protected probes become highly fluorescent after acid‐induced deprotection.     

电化学“沾笔”纳米刻蚀及其他

本文提出了一种基于“沾笔”纳米刻蚀和电化学还原技术在表面上制备金属及半导体纳米结构的普适性方法。用这种方法可以在硅表面直接书写线宽度低于50纳米的多种金属和半导体组成的纳米结构。这种简单而有效的方法在精确控制位置和结构的功能化纳米器件制备中具有重要的潜在应用前景。     

先进光刻胶材料的研究进展

本文简述了光刻技术及光刻胶的发展过程,并对应用于193纳米光刻和下一代EUV光刻的光刻胶材料的研究进展进行了综述,特别对文献中EUV光刻胶材料的研发进行了较为详细的介绍,以期对我国先进光刻胶的研发工作有所帮助.