Review Articles in 2019

Despite their excellent macroscopic operational parameters, halide perovskites exhibit heterogeneity in materials properties at all lateral and vertical length scales. In this Review, we discuss the nature of heterogeneity in halide perovskites and assess the impact of these non-uniformities on their optoelectronic properties and how the heterogeneity may even be beneficial for device properties.

Materials with vanishingly small dielectric permittivity, known as epsilon-near-zero materials, enable strong ultrafast optical nonlinear responses within a sub-wavelength propagation length. This Review surveys the various observations of nonlinear phenomena in this class of materials.

High-entropy alloys have greatly expanded the compositional space for alloy design. In this Review, the authors discuss model high-entropy alloys with interesting properties, the physical mechanisms responsible for their behaviour and fruitful ways to probe and discover new materials in the vast compositional space that remains to be explored.

Topological nanomaterials exhibit enhanced topological surface states and are thus promising for next-generation electronic devices and quantum computations. This Review discusses synthesis and transport results of topological nanomaterials, with a special focus on 1D topological superconductivity realized using topological insulator nanowires.

Supramolecular gels comprise low-molecular weight gelators that assemble by non-covalent interactions. In this Review, a range of fabrication methods, as well as strategies for shaping, structuring and patterning supramolecular gels are discussed.

Type 1 diabetes is an autoimmune disease that causes the destruction of pancreatic β-cells, which results in an insulin deficiency. In this Review, the authors discuss immunomodulatory biomaterials for β-cell replacement and for the induction of tolerogenic immune responses to prevent, delay or reverse the disease.

Nanoscale and microscale materials can be used as drug delivery vehicles to target specific lymph node-resident cell subtypes for immunotherapy. In this Review, the authors discuss the transport mechanisms to and from lymph nodes and how they can be explored for drug delivery.

Cancer nanomedicine in combination with immunotherapies offers the possibility to amplify antitumour immune responses and to sensitize tumours to immunotherapies. In this Review, the authors discuss combination immunotherapy based on nanoparticle platforms designed for chemotherapy, photothermal therapy, photodynamic therapy, radiotherapy and gene therapy.

Macroscale delivery devices can be used to manipulate innate and adaptive immune responses. In this Review, the authors highlight important cellular targets of immunotherapies in tissue repair and cancer and discuss macroscale biomaterials strategies for therapeutic immunomodulation.

Recent breakthroughs in crystal structure prediction have enabled the discovery of new materials and of new physical and chemical phenomena. This Review surveys structure prediction methods and presents examples of results in different classes of materials.

Engineering immune cells and organs using materials enables the investigation of immune responses and the development of immunotherapies. In this Review, the authors discuss 2D and 3D approaches to recreate key cell-level, tissue-level and organ-level immune functionalities of primary, secondary and tertiary lymphoid organs.

Polymers are ubiquitous in batteries as binders, separators, electrolytes and electrode coatings. In this Review, we discuss the principles underlying the design of polymers with advanced functionalities to enable progress in battery engineering, with a specific focus on silicon, lithium-metal and sulfur battery chemistries.

The mechanical properties of blood play an important role in determining blood behaviour in health and disease. In this Review, the authors discuss materials for the recreation of the microenvironment of blood cells and the concept of mechanical homeostasis in blood vessels, blood and blood clots.

Oxide superlattices reveal emergent phenomena if the balance between competing degrees of freedom is altered. In this Review, synthetic approaches to tap the properties of competing ground states are described, focusing on two examples — one example yielding a room-temperature multiferroic and a second producing polarization skyrmions.

Ferroelectrics-based materials can display a negative capacitance (NC) effect, providing an opportunity to implement NC in electronic circuits to improve their performance. In this Review, the authors discuss static and transient NC responses in ferroelectrics and highlight proof-of-concept experiments and possibilities for device implementation.

Adding a third component into a binary blend is a promising strategy for simultaneously improving all photovoltaic parameters in organic solar cells. In this Review, we discuss the role of the third component in influencing the energetics, charge-carrier recombination and stability in ternary solar cells.

This Review outlines the ability of DNA to direct the organization of particle-based building blocks into crystalline architectures. These advancements permit programmable control of each structural element of colloidal crystalline materials and enable the design of functional and responsive behaviours.

Metal halide perovskite nanostructures are promising materials for optoelectronic applications. In this Review, we discuss the synthesis and properties of 1D and 2D single-crystal perovskite nanostructures, examine potential optoelectronic applications and highlight recent studies in which these nanostructures have been used to study the fundamental properties of perovskites.

Laser pulses can trigger fast changes in magnetic state, facilitating new magnetic data storage and memory devices. This Review outlines the mechanisms of all-optical switching and the materials suitable for the optical control of magnetism and tests these mechanisms and materials in terms of speed, accompanying dissipations and scalability. Finally, the large-scale integration of devices in memory applications with low-energy dissipations is discussed.

Mucus is a 3D hydrogel composed of mucins that houses the human microbiome. Mucus guides microbial cell fate and is involved in the suppression of pathogenic bacteria. In this Review, the authors discuss the design of synthetic mucins for the investigation of mucus–microbiome interactions and for applications in 3D in vitro cell culture.