Soft materials

Here the authors investigate lipid nanodiscs as drug carriers for antitumour immunotherapy. They demonstrate that flexible lipid nanodiscs functionalized with STING-activating cyclic dinucleotides exhibit superior tumour penetration and tumour cell uptake compared with spherical liposomes, resulting in improved antitumour T-cell priming and tumour regression.

Highly stretchable organic electrochemical transistors with stable charge transport under severe tensional strains are demonstrated using a honeycomb semiconducting polymer morphology, thereby enabling controllable signal output for diverse stretchable bioelectronic applications.

Two monomers with distinct solubility of their corresponding polymers in an ionic liquid enable tuning of the microstructure of the copolymers during their polymerization. Thus, energy dissipative and elastic molecular domains are created, resulting in highly tough and stretchable ionogels.

Molecular weaving is the entanglement of one-dimensional flexible molecules into higher-dimensional networks. This Perspective provides an overview of the progress so far, and discusses the future challenges and potentials of this field.

The liquid nature of hard glasses is demonstrated by broadband stress relaxation experiments. The rheology and dynamic transition of various glass systems can be unified by a universal scaling law in the time–stress–temperature–volume domain.

Symmetry breaking in colloidal crystals is achieved with DNA-grafted programmable atom equivalents and complementary electron equivalents, whose interactions are tuned to create anisotropic crystalline precursors with well-defined coordination geometries that assemble into distinct low-symmetry crystals.

Glass-like supramolecular polymer networks with high compressibility and fast self-recovery are fabricated using host–guest crosslinkers with slow dissociation kinetics.

The tunability of covalently bound cationic and anionic moieties of zwitterionic materials makes them attractive for potential applications. A family of zwitterions exhibiting molecular disorder and plasticity allows their use as a solid-state conductive matrix.

The large-scale fabrication of cellulose nanocrystal photonic films in a roll-to-roll device is achieved by careful optimization of the cellulose nanocrystal formulation and its controlled deposition and drying on a substrate. Once dry, these photonic films can be peeled and milled into effect pigments, highlighting the potential of cellulose nanocrystals as a sustainable material for industrial photonic applications.

The solvent-free conversion of phthalonitrile derivatives into phthalocyanines in the bulk is described, involving a reductive cyclotetramerization step and the formation of one-dimensional single-crystalline fibres. This solvent-free autocatalytic supramolecular polymerization may enable for a sustainable fabrication of multi-block supramolecular copolymers.

Micromagnets dispersed in a polymer matrix are used to realize a soft magnetoelastic generator with high magnetomechanical coupling factor, used for wearable and implantable power generation and sensing applications.

Pneumatically actuated membranes made from a chiral nematic liquid crystalline elastomer supported by poly(dimethylsiloxane) layers are assembled into pixelated colour devices, where each individual pixel can be tuned throughout the entire visible spectrum.

A two-dimensional hole gas with high carrier density is confined at the interface between a solution-processed, single-crystalline organic semiconducting film and the electric double layer formed by an ion gel on top of the film.

Metal nanolattices are fabricated at an unprecedented scale by using a crack-free self-assembly method. The dense nanostructures enable tensile strengths that approach the theoretical limit.

Programmable triangular DNA blocks self-assemble into distinct icosahedral shells with specific geometry and apertures that can encapsulate viruses and decrease viral infection.

A model describing the behaviour of charge carriers in semiconducting polymers both in the hopping-like and metal-like regimes is developed, and used to quantify charge carrier localization and other transport parameters in organic semiconductors.

Charged colloidal systems undergo fast crystallization under deep supercooling due to a coupled mechanism involving the discrete advancement of the crystal growth front and defect repair inside the recently formed solid phase.

Developing safe electrolytes compatible with high-energy-density electrodes is key for the next generation of lithium-based batteries. Stable solid-state rigid-rod polymer composite electrolytes with nanocrystalline lithium ion pathways are now proposed.

A framework for the elastohydrodynamic lubrication between soft patterned surfaces identifies the contributions of substrate elasticity and pattern geometry for friction, which have implications for the engineering of haptic soft materials.

Stacked elastomeric arrays containing plasmonic nanoparticles show efficient chiral responses that can be fully controlled by mechanical compression and stack rotation. These simple layered materials may be useful modulators for photonic applications.

Highly ordered crystalline porous solids are useful for many applications. This Perspective explores the evolution of these systems from the ordered state to the glassy and liquid states, discusses the different types of porous liquid and considers possible applications of these disordered systems.

A polymer gel composite self-strengthens in response to mechanical vibrations due to activation of mechanically sensitive ZnO crosslinking agents in its matrix, in a process that resembles bone remodelling observed in animals.

Light-responsive myosin motors enable spatial and temporal control over the dynamics and transport of active nematic liquid crystals composed of actin filaments and myosin at an oil–water interface.

Conductors made of a mixture of liquid and solid domains of Ga–In alloy can be stretched over 1,000%, keeping almost constant conductivity, and used to connect commercial electronic components and realize stretchable multilayer printed circuit boards.

Coating of liquid metals on electrospun elastomeric fibre mats leads to the realization of conducting buckled meshes that can be stretched up to 1,800% strain while preserving both stable electrical properties and permeability to air and moisture.

Upon light stimulation, two jointed liquid crystalline network oscillators affect the movement of each other, achieving synchronized in-phase and anti-phase oscillations that can be explored to generate soft actuators with collective responses.

Ionizable phospholipid nanoparticles have been designed to efficiently destabilize endosomal membranes and mediate organ-selective mRNA delivery and CRISPR–Cas9 gene editing.

Elastomers swollen with solvent repeatedly snap back and forward as the solvent evaporates, which is harnessed to fabricate polymeric devices that jump autonomously.

Hierarchically structured 3D materials made of distinct colloidal particles spontaneously assemble by combining the electrostatic modulation of particle interactions to form supracolloids that are organized into 3D structures on solvent drying in an entropy-driven process.

Studies on the morphology stability of polymer donor–small-molecule acceptor blends relevant to solar cell stability reveal relationships between their intermolecular interactions and the thermodynamic, kinetic, thermal and mechanical properties.

Periodic patterns with varying cross-linking densities are realized in conjugated polydiacetylene films, creating multiple holographic images—all dynamically responsive to exposure to various solvents—simultaneously in the same polymeric structures.

A systematic analysis of a series of donor–acceptor organic blends shows that in solar cells based on low-bandgap non-fullerene acceptors an ionization energy offset of about 0.5 eV is required to ensure efficient charge separation.

A graphene nanocomposite hydrogel showing anisotropic swelling is used to realize an electrically conducting and removable bioadhesive that improves the mechanical and electrical integration of bioelectronics devices with wet dynamic tissues.

Experiments and molecular dynamics simulations show that the dehydration-induced actuation of nanoporous tripeptide crystals is a result of pore contraction caused by the strengthening of the water hydrogen-bonding network inside the pore, which creates mechanical stress that deforms the crystal lattice.

Numerical simulations allow the prediction of domain morphology, from aligned to stretched and isotropic, in crystalline organic thin films formed by meniscus-guided coating, as a function of various deposition parameters.

Hybrid colloidal suprastructures and superlattices are assembled by exploring depletion forces to selectively control the interactions between colloidal particles.

The physical vapour deposition of ultrastable monodispersed polymer glasses is reported. This technique allows for the high tunability of glass transition temperatures of the deposited polymers, which could be useful for technological applications.

Relaxor ferroelectric polymers are a material of choice for applications such as electrostrictive actuators or electrocaloric cooling. Here, the origin of relaxor behaviour at the molecular level is investigated and found to arise from conformational disorder.

Peptide amphiphile supramolecular polymers with a crosslinked spiropyran network respond to light by expelling water, enabling the fabrication of soft actuators or light-driven crawlers.

A cell culture interfacing an organic neuromorphic device in a microfluidic system reversibly modifies the device synaptic weight through chemical reactions mediated by the release of dopamine, a neurotransmitter used in biological synapses.

Doping through spontaneous electron transfer between donor and acceptor polymers is obtained by selecting organic semiconductors with suitable electron affinity and ionization energy, achieving high conductivity in blends and bilayer configuration.

The progressive stiffening of the solid–solid contacts that freeze dense colloidal suspensions are shown to cause the macroscopic ageing of such materials.

Chemisorbed molecules combining glycol-ether moieties and fullerenes are shown to form uniform and air-stable self-assembled bilayers on coinage metals, and are amenable to versatile functionalization by in-place exchange of the top layer.

Three-dimensional DNA frames can be created with controlled valence and coordination for the assembly of ordered arrays of biological and inorganic nanomaterials.

Photopolymerization-induced phase separation of resins enables the high-resolution 3D printing of glass oxides with intricate shapes and distinct chemical composition.

The generation of aligned extracellular matrices by fibroblasts is shown to depend on cell reorientation following collision, leading to closer alignment of the cells’ long axes. This cell collision guidance depends on the transcription factor TFAP2C and localized regulation of actomyosin contractility.

Low-dose liquid-phase transmission electron microscopy, particle tracking and numerical simulations are used to characterize the crystallization kinetics and pathways of gold nanoprisms at the single-particle level.

Repetitive electrical pulse stimulation of blue-phase liquid crystals promotes their reconfiguration into stable non-cubic structures with promising electro-optical responses for display technologies.

The kinetics and thermodynamics of the nucleation of magnetite crystals from primary particles are shown to be described by colloidal assembly theory, allowing for predictions of crystal sizes to be made.