It is hard to overstate the importance of developing novel functional materials and surfaces, which are often essential for meeting challenges in diagnostics, biotechnology, tissue engineering, optics, microfluidics, and many other fields. A central question is how to generate novel complex functionality or properties that would go beyond those of existing materials and surfaces. This question is being approached from numerous angles, among them inspiration from biological systems (biomimetics), combinatorial synthesis and high‐throughput screening of novel materials, synergistic combination of different components or processes, as well as the assembly of microscopic building blocks into macroscopic materials.

In this Special Issue of Advanced Functional Materials, “Assembly of Materials Building Blocks into Integrated Complex Functional Systems” we received 22 excellent papers presenting original research as well as reviews on this topic. These articles demonstrate the growing diversity of strategies for fabricating novel classes of materials in which complex functionalities emerge from the assembly of materials building blocks or the synergistic combination of components and processes. This editorial highlights a subset of representative examples to give a flavor of published research articles and the future potential of this scientific field.

One example where large complex 3D functional materials are created through the assembly of small materials building blocks (voxels) is discussed in an article by Wegener et al. (article number 1907795), in which the authors review 3D additive manufacturing approaches in terms of maximum voxel printing rate and minimum voxel size. The authors also present a new multi‐focus two‐photon 3D printing technology that approaches total printing speeds of ten million voxels per second at sub‐µm voxel sizes, which significantly surpasses previous top printing speeds. Fabrication of functional responsive 3D materials is reviewed by Blasco et al. (article number 1907615). The article discusses 3D printing of adaptive and dynamic structures (4D printing), where the additional dimension refers to the ability of the structures to change their shape in response to a stimulus. One example of such dynamic properties is based on the formation of hetero‐microstructures combining materials with different swellability or different response characteristics. Assembling such microscopic “hetero” building blocks into a macroscopic structure can lead to interesting dynamic macroscopic properties.

In nature, tissues are built through the hierarchical organization of microscopic “building blocks” into progressively larger and more complex structures. Bioinspired tissue engineering often relies on the assembly of microscopic artificial soft building blocks into macroscopic functional tissue‐like structures. Stevens et al. (article number 1909009) give an overview of the recent progress and trends in the fabrication and assembly of living building blocks, with a key highlight on emerging bioprinting technologies that can be used for modular assembly and complexity in tissue engineering. Such living building blocks include single cells, cell fibers, cell sheets, cell spheroids and cell organoids, which can be assembled into various complex functional living structures (tissue engineering). Development of methods to create functional soft materials is essential due to the complexity of living tissues and organs that have to be mimicked to meet need in areas such as regenerative medicine and novel functional implants. Thus, cell‐instructive multiphasic gel‐in‐gel materials based on combination of different types of hydrogel building blocks are reviewed by Werner et al. (article number 1908857). The final functionality and properties of such materials depend, to a great extent, on the architecture of such heterogeneous and multiphasic materials, for example, layered, embedded or bundled organization.

Design of adhesives for affixing soft hydrogel building blocks is challenging and crucial for creating complex hydrogel structures. Lee et al. (article number 1908497) demonstrate how alginate‐boronic acid‐based glue has been used to attach diverse hydrogel building blocks to create complex soft macroscopic hydrogel structures. In another related progress report, Khademhosseini et al. (article number 1909882) review components of synthetic biology that can serve as building blocks to engineer cells in tissues with higher degrees of cellular complexity and function.

Bottom‐up self‐assembly is another approach to assembling complex functional structures from small building blocks. Thus, Noorduin et al. (article number 1908218) demonstrate the bottom‐up self‐assembly of simple nanoscopic mineral (barium carbonate/silica) building blocks into complex architectures (double helices) with specialized and finely controlled optical properties. Due to such double helical organization, these self‐assembled architectures emit highly directional light along their long axes, while affecting a differential refraction of left and right circularly polarized light. Li et al. investigate the assembly of nano‐ or microscopic objects into more complex packed structures. The presented approach harnesses the crack formation as a patterning tool to fabricate microscopic photonic structures with controlled sizes and geometries (article number 1908242). Steady‐state, light‐adaptive reconfiguration of mechanical patterns under dissipative out‐of‐equilibrium conditions through the combination of heterogeneous activation of a photo‐thermal effect is reported by Walther et al. (article number 1905309). Assembly of molecular building blocks into integrated MOF/COF‐based functional systems is reviewed by Bräse et al. (article number 1907625).

Vogel et al. (article number 1907730) report an interesting study on controlled colloidal assembly inside of droplets, resulting in structural color. In addition, the rotational motion, dynamics and crystallization of such micron‐scale clusters suspended in a liquid could be followed in real time via their anisotropic coloration, demonstrating that structural color is a simple and versatile tool to characterize the structure and dynamic properties of colloidal clusters. Ionov et al. (article number 1908028) discuss the principles of the formation of complex functional devices based on shape memory materials. Combination of shape memory effects with different stimuli and different shapes and architectures leads to applications in the field of soft‐robotics, microfluidics, sensors, smart textiles, medicine or drug delivery.

In addition to the combination of building blocks, novel complex functionality can be generated through the synergistic combination of opposing processes (rather than properties). Scheiger et al. (article number 1909800) demonstrate hydrogels with pre‐programmable lifetime, which was achieved through the combination of UV‐induced polymerization with UV‐induced photodegradation in the same material.

Incorporation of reactive dynamic bonds into a coating can lead to novel macroscopic surface properties, such as the possibility to repair the functionality, change its properties such as hydrophobicity or hydrophilicity, or create patterns of properties. In this realm, Butt et al. (article number 1907605) review reconfigurable surfaces based on photo‐controlled dynamic bonds including thiol‐quinone methide, disulfide exchange, thiol‐disulfide interconversion, diselenide exchange, and photosubstitution of Ru complexes.

These are just a sampling of the many creative research directions discussed in this Special Issue. Also included are excellent research articles and reviews discussing topics such as microsphere design via visible‐light cross‐linking of functional prepolymers (article number 1905399), multi‐functional (super)wetting surfaces (article number 1907772), challenges of self‐healing in anti‐fouling materials (article number 1908098), cell encapsulation systems for modular tissue regeneration (article number 1908061), or self‐assembly in hopper‐shaped crystals (article number 1908108).

Finally, Lahann et al. (article number 1907865) investigated the magnetically directed spatiotemporal self‐assembly and switching of magnetic janus particles. Progress in the development of nanogeneratores is discussed by Wang et al. (article number 1908252), while Greiner et al. (article number 1907555) reported fabrication of flexible low‐resistance membranes with the reversible change in resistance, potentially useful for smart wearables.

Together, this collection of papers provides both an inspiring display of the many complex functions—and beauty—that can arise from assembling and combining even well‐known building blocks, and a wealth of insight into the growing variety of routes to accessing and discovering such novel and critical materials.

很难夸大开发新型功能材料和表面的重要性，这对于迎接诊断，生物技术，组织工程，光学，微流体和许多其他领域的挑战通常是必不可少的。一个中心问题是如何产生超越现有材料和表面的新颖复杂功能或特性。这个问题的解决方法有很多种，其中包括生物系统（仿生物），新型材料的组合合成和高通量筛选，不同组分或工艺的协同组合以及将微观构件组装成宏观材料的灵感。 。

在本期高级功能材料特刊“将材料构建基块组装到集成的复杂功能系统中”中，我们收到了22篇优秀论文，介绍了原创研究以及对该主题的评论。这些文章证明了制造新型材料类别的策略日益多样化，在这些类别中，复杂功能是从材料构造块的组装或组件与过程的协同组合中产生的。这篇社论重点介绍了代表性实例的子集，以提供已发表的研究文章的风味以及该科学领域的未来潜力。

Wegener等人在一篇文章中讨论了一个通过组装小型材料构建块（体素）来创建大型复杂3D功能材料的示例。（文章编号1907795），其中作者从最大体素打印速率和最小体素尺寸方面回顾了3D增材制造方法。作者还提出了一种新的多焦点双光子3D打印技术，该技术在亚微米体素大小下的每秒总打印速度接近一千万个体素，大大超过了以前的最高打印速度。Blasco等人综述了功能敏感的3D材料的制造。（商品编号1907615）。本文讨论了自适应和动态结构的3D打印（4D打印），其中，附加维度是指结构响应刺激而更改其形状的能力。这种动态特性的一个例子是基于异质微结构的形成，这些异质微结构结合了具有不同膨胀性或响应特性的材料。将这样的微观“异质”构建基块组装成宏观结构可以带来有趣的动态宏观特性。

在自然界中，组织是通过微观“构件”的分层组织而逐渐形成更大，更复杂的结构的。受生物启发的组织工程通常依赖于将微观的人造软构件组装成宏观的功能性组织样结构。史蒂文斯等。（文章编号1909009）概述了活动构建块的制造和组装的最新进展和趋势，重点介绍了可用于模块化组装和组织工程复杂性的新兴生物打印技术。这样的生物构件包括单个细胞，细胞纤维，细胞片，细胞球体和细胞类器官，它们可以组装成各种复杂的功能性生物结构（组织工程）。由于必须模仿活组织和器官的复杂性来满足诸如再生医学和新型功能植入物等领域的需求，因此开发功能性软材料的方法至关重要。因此，Werner等人综述了基于不同类型水凝胶构件的细胞指导性多相凝胶材料。（商品编号1908857）。这种材料的最终功能和特性在很大程度上取决于这种异质和多相材料的体系结构，例如分层，嵌入或捆绑的组织。Werner等人综述了基于不同类型水凝胶构件的细胞指导性多相凝胶材料。（商品编号1908857）。这种材料的最终功能和特性在很大程度上取决于这种异质和多相材料的体系结构，例如分层，嵌入或捆绑的组织。Werner等人综述了基于不同类型水凝胶构件的细胞指导性多相凝胶材料。（商品编号1908857）。这种材料的最终功能和特性在很大程度上取决于这种异质和多相材料的体系结构，例如分层，嵌入或捆绑的组织。

用于固定软水凝胶构件的粘合剂的设计对于形成复杂的水凝胶结构而言是具有挑战性和至关重要的。Lee等。（文章编号1908497）展示了如何使用基于藻酸盐-硼酸的胶水附着各种水凝胶构件，以创建复杂的宏观软水凝胶结构。在另一个相关的进度报告中，Khademhosseini等人。（第1909882号文章）综述了合成生物学的组成部分，这些组成部分可以用作构建组织中具有更高程度的细胞复杂性和功能的细胞的基石。

自下而上的自组装是从小型构建块组装复杂功能结构的另一种方法。因此，Noorduin等。（文章编号1908218）展示了自底向上的自组装，将简单的纳米级矿物（碳酸钡/二氧化硅）构建基块组装成具有特殊且精细控制的光学特性的复杂体系结构（双螺旋）。由于这种双螺旋结构，这些自组装的体系结构沿其长轴发出高方向性的光，同时影响左右圆偏振光的微分折射。Li等。研究将纳米或微观物体组装成更复杂的包装结构。提出的方法利用裂纹形成作为图案化工具来制造尺寸和几何形状受控的微观光子结构（商品编号1908242）。Walther等人报道了通过光热效应的异质激活相结合，在耗散失衡条件下机械模式的稳态，光适应性重构。（商品编号1905309）。Bräse等人综述了将分子构件组装到基于MOF / COF的集成功能系统中的过程。（商品编号1907625）。Bräse等人综述了将分子构件组装到基于MOF / COF的集成功能系统中的过程。（商品编号1907625）。Bräse等人综述了将分子构件组装到基于MOF / COF的集成功能系统中的过程。（商品编号1907625）。

Vogel等。（文章编号1907730）报告了有关液滴内部胶体组装受控，产生结构颜色的有趣研究。此外，悬浮在液体中的此类微米级团簇的旋转运动，动力学和结晶可以通过各向异性着色实时跟踪，表明结构色是表征胶体结构和动力学性质的简单通用工具集群。Ionov等。（文章号1908028）讨论了基于形状记忆材料的复杂功能器件的形成原理。形状记忆效应与不同的刺激，不同的形状和结构相结合，可在软机器人，微流体，传感器，智能纺织品，药物或药物输送领域中得到应用。

除了构建块的组合之外，还可以通过相反过程（而不是属性）的协同组合来生成新颖的复杂功能。Scheiger等。（文章编号1909800）展示了具有可预编程寿命的水凝胶，这是通过在同一材料中将UV诱导的聚合与UV诱导的光降解相结合而实现的。

将反应性动态键结合到涂层中可导致新的宏观表面性质，例如修复功能性，改变其性质（例如疏水性或亲水性）或创建性质图案的可能性。在这个领域，Butt等人。（文章编号1907605）综述了基于光控动态键的可重构表面，其中包括硫醇-醌甲基化物，二硫键交换，硫醇-二硫键互变，二硒化物交换和Ru络合物的光解性。

这些只是本期特刊中讨论的许多创造性研究方向的样本。还包括出色的研究文章和评论，讨论诸如通过功能性预聚物的可见光交联进行微球设计（文章编号1905399），多功能（超）润湿表面（文章编号1907772），自修复的挑战等主题。防污材料（商品编号1908098），用于模块化组织再生的细胞封装系统（商品编号1908061）或在料斗形晶体中自组装（商品编号1908108）。

最后，Lahann等。（文章编号1907865）研究了磁性剑指粒子的磁定向时空自组装和转换。Wang等人讨论了纳米发电机的开发进展。（文章编号1908252），而格赖纳（Greiner）等人。（文章编号1907555）报道了具有低可逆电阻变化的柔性低电阻膜的制造，可能对智能可穿戴设备有用。

在一起，这些论文集既令人鼓舞地展示了许多复杂功能（和美感）的产生，它们甚至可以通过组装和组合著名的构建基块而得到，并且对获取和发现此类功能的不断增长的各种途径具有丰富的见解。新颖而关键的材料。