Dear Readers,

Like many other things we had planned for summer 2020, the Annual Symposium Engineering of Functional Interfaces could not take place. It was scheduled for July 2020 in Maastricht, the Netherlands, when the worldwide stop of meetings, conferences, symposia, business trips, university lectures and private meetings switched everything on hold: Biological nanoparticles attained a very specific focus, dramatically influencing our daily life.

Those of us, who are working in the scientific field of the engineering of functional interfaces, including students and senior researchers, had already done considerable work in this area. It was therefore a logical step to continue with the annual special issue of physica status solidi A for communicating the latest results in original research articles and summarizing the state-of-the-art in review-style feature articles, despite the given situation and despite the cancellation of the symposium. The editor-in-chief immediately agreed when we proposed to edit a special issue that is not based on a real symposium for now, just to continue a swift communication. Like in the years before, we received the full support from the editorial team.

We would like to express our sincerest thanks to all contributors and in particular to all peer reviewers, who again helped us with their critical, stimulating and motivating opinion to maintain the high level of science in this special issue. The latter must be emphasized during such changing times in which all of us have a lot of additional burdens to carry.

Regarding science, this issue consists of eight original research articles ranging from corrosion studies on HVOF coatings, over the self-assembly of membranes and biomimetic deposition methods, modelling of semiconductor hetero-structures, to bio-analytical sensors with task-specific receptor layers for applications in medical diagnostics and food-quality monitoring. Furthermore, there are two feature articles: One of them deals with the rational design of molecularly imprinting polymers for extracting residues of antibiotics from food- and environmental samples. The second one documents the strategies of industrial sterilization processes, covering all aspects from the perspective of surface-physics and chemistry, and provides a technological forecast on this field.

This series of annual special issues of physica status solidi A on the Engineering of Functional Interfaces will continue and is already open for submission as it has established itself as a valuable medium for the communication of targeted scientific results. If you are working in the field, please consider contributing an article. If you are not publishing in this field but you are interested in reading these articles, please feel free to check the homepage of PSS A regularly: All articles will be published online without delay, before being compiled next year in a printed issue.

Some of the conferences in the world are held online, however, this format is not considered to be appropriate for the EnFI Symposium. Its structure with only a few keynote lectures and many short appetizers for the poster sessions, being the core medium of this conference, cannot be mimicked via zoom or other platforms. The countless small discussions amongst the participants, the valuable hints from experienced scientists, the training for students in presenting their results – all this requires a “direct contact”. Whether or not the next EnFI will be held in 2022 or only later, we all hope that we get back to our scientific course of the year with dedicated times of harvesting while maintaining the positive aspects of what we have learned during this crisis.

Please enjoy reading these articles and the science behind to stimulate your own research activities!

The Guest Editors

Patrick Wagner, KU Leuven

Achim Walter Hassel, Johannes Kepler University Linz

Michael J. Schöning, Aachen University of Applied Sciences

亲爱的读者，

与我们为 2020 年夏季计划的许多其他事情一样，功能接口工程年度研讨会未能举行。它原定于 2020 年 7 月在荷兰马斯特里赫特举行，当时全球范围内的会议、大会、座谈会、商务旅行、大学讲座和私人会议都暂停了：生物纳米颗粒获得了非常具体的关注，极大地影响了我们的日常生活。

我们这些在功能接口工程科学领域工作的人，包括学生和高级研究人员，已经在这方面做了大量工作。因此，尽管存在特定情况，但继续发行physica statussolidi A的年度特刊是合乎逻辑的步骤，以在原始研究文章中交流最新结果并总结评论式专题文章的最新技术水平研讨会的取消。当我们提议编辑一个暂时不是基于真正研讨会的特刊时，主编立即同意了，只是为了继续快速沟通。与前几年一样，我们得到了编辑团队的全力支持。

我们要向所有贡献者，特别是所有同行评审人员表示最诚挚的感谢，他们再次以批判性、刺激性和激励性的意见帮助我们保持本期特刊的高科学水平。在我们所有人都有很多额外负担要承受的变化时代，必须强调后者。

关于科学，本期由八篇原创研究文章组成，范围从 HVOF 涂层的腐蚀研究、膜的自组装和仿生沉积方法、半导体异质结构的建模，到具有任务特定受体层的生物分析传感器在医疗诊断和食品质量监测中的应用。此外，还有两篇专题文章：其中一篇涉及分子印迹聚合物的合理设计，用于从食品和环境样品中提取抗生素残留物。第二篇记录了工业灭菌过程的策略，从表面物理和化学的角度涵盖了各个方面，并提供了该领域的技术预测。

这一系列关于功能接口工程的physica statussolidi A年度特刊将继续进行，并且已经开放提交，因为它已成为交流有针对性的科学成果的宝贵媒介。如果您在该领域工作，请考虑贡献一篇文章。如果你不是在这个领域发表文章，但你有兴趣阅读这些文章，请随时查看PSS A的主页：所有文章将立即在线发布，然后在明年编译成印刷版。

世界上的一些会议是在线举行的，但是，这种形式被认为不适合 EnFI 研讨会。它的结构只有少数主题演讲和许多海报会议的简短开胃菜，是本次会议的核心媒体，是zoom或其他平台无法模仿的。参与者之间无数的小讨论、经验丰富的科学家的宝贵提示、对学生展示结果的培训——所有这些都需要“直接接触”。无论下一次 EnFI 是在 2022 年还是以后举行，我们都希望我们能在专注于收获的时间回到我们一年中的科学课程，同时保持我们在这场危机中学到的积极方面。

请尽情阅读这些文章和背后的科学，以激发您自己的研究活动！

客座编辑

帕特里克·瓦格纳，鲁汶大学

Achim Walter Hassel，约翰内斯开普勒大学林茨

Michael J. Schöning，亚琛应用科学大学