Dear colleagues,

On the next pages you will find a collection of seventeen articles devoted to the broad topic “Engineering of Functional Interfaces”. Surfaces and interfaces with task‐specific, tailored properties and functionalities are literally everywhere in daily life, ranging from catalysts and anticorrosive coatings to consumer electronics and health care. Any diode, transistor, solar cell, glucose sensor or pacemaker electrode can only function through the intimate contact between two or more materials and the way they interact with each other. Hence, there are countless and mature applications in which functional interfaces play their enabling role already today. But research and development do surely not slow down, there are several driving forces:

First, the principles behind self‐assembly and structure formation become better and better understood, both along the top‐down and the bottom‐up routes, which allows to add entirely new functionalities to well‐known materials. The cover article by Tomohiro Inoue (Hokkaido University) and his co‐workers on liquid‐infused, hierarchically patterned aluminium is a beautiful example how to teach this metal the new trick to behave strongly repellent for ice formation. The technical and economic relevance is immediately clear while it needs considerable expertise and creativity to come up with such non‐trivial solutions to hitherto unsolvable problems. Other examples that the form of a metal enables peculiar functions come from the biomedical field with new applications for copper nanowires and laser‐patterned titanium to stimulate the adhesion of bone cells.

Metals and their oxides play, not in the least, also a key role in novel corrosion‐resistant coatings and as electrode materials in the run for an even better performance of solid‐state, lithium‐ion batteries.

A second driver for progress in surface‐ and interface engineering are powerful analytical tools such as Raman scattering, dielectric spectroscopy, and dissipation‐sensitive microbalances. The working principles are well known and established, but these tools come today in combinations, allowing to gain complementary information simultaneously, while substantial improvements in lateral resolution enable imaging capabilities. We illustrate this in selected publications on the study of phospholipids and their vesicles, on the curing and ageing of polymers, and on probing the dielectric behaviour of polystyrene down to the scale of nanoparticles. The aim of characterizing properties of nanoscale objects gives also a boost in the opposite direction by stimulating the development of new analytical tools, upgrading the existing ones, and getting control in complex situations when observables start to interfere.

A large field, in which practically all is about a functional interface, are bio‐ and chemo‐sensors; for them, the needs of health care and well‐being are major drivers: Surfaces are functionalized in a way that they recognize and bind “targets” that can range from DNA fragments and small molecules such as neurotransmitters to proteins, viruses, cells and bacteria. While the selective recognition is a matter of biochemistry, the signal generation of the transducer relies on physics‐ and physicochemical effects. Also here we see a trend to parallelization, allowing to probe several parameters of the targets at the same time, or to detect different target types simultaneously and in a spatially resolved manner. Engineering is not limited to modifying a surface, also the receptors, with aptamers as a speaking example, are often smart pieces of molecular engineering to enable the selective binding of targets just as an antibody would do.

The concluding part with three articles is devoted to the development of sensors systems in which, for instance, 3D‐printing gives considerable freedom for the fast prototyping of new instruments. Furthermore, sensor‐ and stimulation systems meant for implantation into the body become more easily to manufacture with biocompatible compounds while wearable electronics comes close to the point of featuring embedded sensing functionalities.

We are sure that many of you will find this collection of articles inspriring and worthwhile to read: They span the bridge from the fundamentals to evolving applications and innovations that will show up sooner or later in daily life. Moreover, these new developments are often based on cooperation between disciplines: Looking at things from different angles always brings about new perspectives and creates a dynamics that will keep the topic of functional interfaces high on the agenda for many years to come.

Last but not least, we would like to thank all authors cordially for their contributions, the peer‐reviewers for their voluntary and well‐willing efforts, and the team of PSS for their helpful advice and hosting this topical issue now already for the twelfth year in a row.

With kind regards,

亲爱的同事们，

在接下来的页面中，您将找到十七篇文章的集合，这些文章专门针对广泛的主题“功能接口的工程设计”。具有特定任务，量身定制的特性和功能的表面和界面在日常生活中几乎无处不在，从催化剂和防腐涂料到消费电子产品和医疗保健。任何二极管，晶体管，太阳能电池，葡萄糖传感器或起搏器电极只能通过两种或多种材料之间的紧密接触以及它们彼此相互作用的方式起作用。因此，当今已经有无数成熟的应用程序在其中功能接口发挥其推动作用。但是研发一定不会减慢速度，这有几个驱动力：

首先，沿着自上而下和自下而上的路线，自组装和结构形成背后的原理越来越好，这为知名材料增加了全新的功能。北海道大学的井上智宏（Tomohiro Inoue）和他的同事撰写的封面文章介绍了如何注入液体，分层图案化的铝，这是一个很好的例子，它可以教给这种金属新的技巧，使其对结冰具有强烈的驱避作用。技术和经济相关性很明显，同时需要大量的专业知识和创造力来提出此类非平凡的解决方案，以解决迄今无法解决的问题。

金属及其氧化物在新型耐腐蚀涂层中也起着关键作用，并且在运行中作为电极材料以提高固态锂离子电池的性能。

强大的分析工具（如拉曼散射，介电谱和对耗散敏感的微量天平）是推动表面和界面工程取得进展的第二个动力。工作原理众所周知并已确立，但是今天这些工具组合起来使用，可以同时获取补充信息，同时横向分辨率的显着提高使成像功能得以实现。我们在有关磷脂及其囊泡的研究，聚合物的固化和老化以及探查聚苯乙烯直至纳米颗粒规模的介电性能的选定出版物中对此进行了说明。通过刺激新分析工具的开发，对现有分析工具的升级，

生物传感器和化学传感器是一个很大的领域，几乎所有功能接口都在其中。对他们而言，医疗保健和福祉的需求是主要驱动力：表面以能够识别和结合“靶标”的方式进行功能化，这些靶标的范围从DNA片段和小分子（例如神经递质）到蛋白质，病毒，细胞和细菌。尽管选择性识别是生物化学的问题，但换能器的信号生成依赖于物理和物理化学效应。同样在这里，我们看到了并行化的趋势，允许同时探测目标的多个参数，或者以空间分辨的方式同时检测不同的目标类型。工程不限于修饰表面，还修饰受体，以适体为例。

最后的三篇文章专门介绍了传感器系统的开发，例如3D打印为快速开发新仪器提供了很大的自由度。此外，意在植入体内的传感器和刺激系统变得更容易使用生物相容性化合物制造，而可穿戴电子设备已接近具有嵌入式传感功能的地步。

我们确信，您中的许多人都会发现这些令人着迷的文章集，这些文章值得阅读：它们跨越了从基础到不断发展的应用程序和创新的桥梁，这些桥梁迟早会出现在日常生活中。而且，这些新的发展通常基于学科之间的合作：从不同角度看待事物总是会带来新的观点并创造动力，这将使功能接口这一主题在未来许多年内一直处于优先地位。

最后但并非最不重要的一点是，我们要衷心感谢所有作者的贡献，同行审稿人的自愿和愿意的努力，以及PSS团队的有益建议，并且已经在第十二届会议上主持了这一专题连续。

亲切的问候，