DNA nanotechnology is a materials design paradigm in which synthetic nucleic acids are used to program the structure and dynamics of nanometer-scale devices and materials. Driven by the convergence of decreasing DNA synthesis costs, advanced yet easy-to-use computational design and analysis tools, and, most importantly, a myriad of innovative studies demonstrating DNA’s extraordinary power to organize functional materials, DNA nanotechnology is spreading into diverse areas of traditional materials science. To further promote the integration of DNA nanotechnology into materials science, this issue of MRS Bulletin provides an overview of the unique capabilities offered by DNA nanotechnology, a set of practical techniques that make it accessible to a broad audience, and a vision for its future applications, described by international leaders in the field.

DNA nanostructures are a set of materials with well-defined physical, chemical, and biological properties that can be used on their own or incorporated with other materials for many applications. Herein, the practical aspects of utilizing DNA nanostructures (structural or dynamic) as materials are comprehensively covered. This article first summarizes properties of DNA molecules and practical considerations and then discusses the fundamental design principles of structural DNA nanostructures. Finally, various aspects of dynamic DNA nanostructure-based actuation and computation are included.

DNA nanotechnology has the power to form self-assembled and well-defined nanostructures, such as DNA origami, where the relative positions of each atom are known with subnanometer precision. Our ability to synthesize oligonucleotides with chemical modifications in almost any desired position provides rich opportunity to incorporate molecules, biomolecules, and a variety of nanomaterials in specific positions on DNA nanostructures. Several standard modifications for oligonucleotides are available commercially, such as dyes, biotin, and chemical handles, and such modified oligonucleotides can be applied directly for integration in DNA nanostructures. In another approach, various molecules and nanomaterials have been functionalized with DNA for incorporation in DNA nanostructures by hybridization to staple strands extending from the origami structure. Multiple copies of functionalities such as hydrocarbons or steroids have been introduced to change the surface properties of DNA origami structures, either to protect the DNA nanostructure or to dock it into membranes and other hydrophobic surfaces. DNA nanostructures have also been used to control covalent chemical reactions. This article provides an introduction to chemical methods applied to DNA nanotechnology and, through examples, shows how this increases the potential of DNA nanostructures as functional nanomaterials.

Structural DNA nanotechnology has been particularly driven toward three-dimensional (3D) construction since its inception at the start of the 1980s. Part of the driving force was the goal of building specific crystals from macromolecular components, without having to use trial and error for determining appropriate crystallization conditions. With the first demonstration of DNA attachment to gold nanoparticles in the 1990s, DNA became a player in inorganic nanomaterials as a programmable agent for structure assembly. For pure DNA structures, the crystallization goal has been mediated by sticky-ended cohesion with some success, although trial and error crystallizations have produced better diffracting crystals than those directed self-assembly. For nanoparticles, different types of 3D nanoscale crystalline organizations have been realized. Recent efforts not only expand the diversity of particle lattices, but also strive to achieve designed lattice symmetries and their transformations. In this article, we review the development of 3D assembly of DNA and DNA-guided nanoparticle arrays, the issues that have prevented and facilitated formation of such structures, and recent strategies toward this goal.

Biological systems illustrate how complex and dynamic physical and chemical interactions between many different components can produce organized structures across length scales, ranging from angstroms to hundreds of meters, and precise temporal control over diverse material dynamics. While mechanisms for pattern formation such as reaction-diffusion processes, message passing, or rule-based assembly have been studied extensively using mathematical models, it can be difficult to create synthetic materials that implement these mechanisms. Here, we describe how DNA nanotechnology techniques make it possible to systematically build systems capable of complex self-organization or pattern formation across scales. DNA-programmed short-range interactions can be used to build aperiodic crystals and assemblies with long-range order, form patterns using reaction-diffusion and chemical message passing, and create self-organizing or stimulus-responsive amorphous materials, including gels or cell-sized compartments. Exploiting principles from self-organization using DNA-based interactions makes it possible to build materials with complex long-range order and intelligent spatiotemporal responses to a variety of stimuli using relatively simple bottom-up methods.

Enzyme sequestration and compartmentalization are key factors in cell signaling and metabolism, evolved to solve the challenges of slow turnover rates, undesired pathway intermediates, and competing reactions. Inspired by nature, DNA nanoengineers have developed organizational systems to confine enzymes in two- and three-dimensional environments and to actuate them in response to precise external stimuli. DNA-scaffolded enzymes have applications for not only the in vitro reconstitution of proteins, peptides, and other molecular assemblies, but also to enable the generation of advanced functional nanomaterials for the development of, for example, fuel cells, biosensors, and drug delivery systems. Despite several challenges that still remain unsolved, the use of DNA scaffolds to arrange enzymes in space and time will help to realize biochemical nanofactories, where multiple components work together to produce novel and improved functional materials, rivaling the efficiency of biological systems.

Structural DNA nanotechnology offers the capacity to construct ultraminiaturized devices with programmed nanoscale geometry, mechanical and dynamic properties, and site-specific molecular functionalities. These features and the possibility to position and orient molecules in user-defined ways may be exploited to create custom instruments for precision measurements of molecular-scale structure, dynamics, and interactions. Such devices may help constrain molecular motion along interesting reaction coordinates and may also exert forces to probe the mechanical properties or dynamics of molecules under study. Multiple ways of reading out device states may be used, including atomic force microscopy or transmission electron microscopy imaging, single-molecule or bulk fluorescence, or ionic conductivity as in nanopore systems. Early successes with custom scientific instruments based on DNA origami underline the tremendous potential to enable new approaches to making scientific discoveries in biological and synthetic materials systems.

RNA nanotechnology seeks to exploit the structural and functional properties of the RNA molecule in order to rationally design RNA nanoparticles and devices for applications in biotechnology and medicine, among others. Compared to DNA, RNA can adopt a larger diversity of structural motifs that allows the construction of more complicated nanoparticles that can be self-assembled during synthesis by the RNA polymerase—a process called co-transcriptional folding. RNA nanostructures can be genetically encoded and co-transcriptionally folded in cells, which allows large-scale production of RNA nanoparticles for therapeutic use or the application as scaffolds in cells for manipulating cellular components for use in synthetic biology. In this article, we describe the origins of the RNA nanotechnology research field and how it has been inspired by DNA nanotechnology. Recent developments of co-transcriptionally folded RNA nanostructures and the construction of RNA knots are discussed in relation to design principles and challenges, and speculations about future directions of the field are provided.

DNA nanotechnology has developed into a state where the design and assembly of complex nanoscale structures is fast, reliable, cost effective, and accessible to nonexperts. Nanometer-precise positioning of organic (e.g., dyes and biomolecules) and inorganic (e.g., metal nanoparticles and colloidal quantum dots) components on DNA nanostructures is straightforward and modular. In this article, we identify the opportunities and challenges that DNA-assembled devices and materials face for optical antennas, metamaterials, and sensing applications. With the ability to arrange hybrid components in defined geometries, plasmonic effects will, for example, amplify molecular recognition transduction such that single-molecule events will be measureable with simple devices. On a larger scale, DNA nanotechnology has the potential to break the symmetry of common self-assembled functional materials, creating predefined optical properties such as refractive-index tuning and topological insulation.

Over the last decade, DNA origami has matured into one of the most powerful bottom-up nanofabrication techniques. It enables both the fabrication of nanoparticles of arbitrary two-dimensional or three-dimensional shapes, and the spatial organization of any DNA-linked nanomaterial, such as carbon nanotubes, quantum dots, or proteins at ∼5-nm resolution. While widely used within the DNA nanotechnology community, DNA origami has yet to be broadly applied in materials science and device physics, which now rely primarily on top-down nanofabrication. In this article, we first introduce DNA origami as a modular breadboard for nanomaterials and then present a brief survey of recent results demonstrating the unique capabilities created by the combination of DNA origami with existing top-down techniques. Emphasis is given to the open challenges associated with each method, and we suggest potential next steps drawing inspiration from recent work in materials science and device physics. Finally, we discuss some near-term applications made possible by the marriage of DNA origami and top-down nanofabrication.

Structural DNA nanotechnology is revolutionizing the ways researchers construct arbitrary shapes and patterns in two and three dimensions on the nanoscale. Through Watson–Crick base pairing, DNA can be programmed to form nanostructures with high predictability, addressability, and yield. The ease with which structures can be designed and created has generated great interest for using DNA for a variety of metrology applications, such as in scanning probe microscopy and super-resolution imaging. An additional advantage of the programmable nature of DNA is that mechanisms for nanoscale metrology of the structures can be integrated within the DNA objects by design. This programmable structure–property relationship provides a powerful tool for developing nanoscale materials and smart rulers.

Materials used in wearable and implantable electronic devices should match the mechanical properties of biological tissues, which are inherently soft and deformable. In comparison to conventional rigid electronics, soft bioelectronics can provide accurate and real-time monitoring of physiological signals, improve comfort, and enable altogether new modalities for sensing. This article highlights recent progress, identifies technical challenges, and offers possible solutions for the emerging field of stretchable bioelectronics. We organize the content into three topical categories: (1) biological integration of soft electronic materials, (2) materials and mechanics, and (3) soft robotics. Finally, we conclude this article with a discussion on the outlook of the field and future challenges.