Volume 20 Issue 12, December 2021

New classes of functional soft materials show promise to revolutionize robotics. Now materials scientists must focus on realizing the predicted performance of these materials and developing effective and robust interfaces to integrate them into highly functional robotic systems that have a positive impact on human life.

The giant magnetoelastic effect measured in magnetic elastomers enables new energy generators for wearable and implantable electronics.

An interplay between deswelling and buckling in a polymer gel is harnessed to achieve sequential snap events for repeatable jumping motion, opening the door to autonomously moving soft robots.

The polar magnetic semimetal NdAlSi hosts Weyl fermions that promote helical magnetism, and defines a roadmap for future work on correlated topological matter.

Coupled liquid-crystalline network oscillators incorporating light-responsive molecules show synchronized motion when stimulated by light. This behaviour resembles that of synchronized clock pendulums and may find uses in advanced soft robotics applications.

Tamm plasmon thermal emitters can provide efficient infrared emission, but are limited by design complexity. Now, the inverse design of Tamm modes facilitated by CdO films on aperiodic dielectric reflectors enables emission with an on-demand spectrum.

By using a battery of experimental and theoretical methods, it is shown that ion intercalation into the electrode material birnessite is mediated by structural water.

Using atomic-resolution electron microscopy to observe ion-exchange processes in atomically thin layered and restacked clays, substantially larger ion diffusion constants and moiré effects on ion dynamics are seen.

This Review focuses on nonlinear electromagnetic responses that arise from quantum geometry and topology.

This Review discusses the photophysical properties and nonlinear behaviour of single molecules, and their use as single-photon sources and in single-molecule sensing and quantum-sensing applications.

Typically undesired chemically heterogeneous microstructures are shown to enhance the resistance of high-strength steel against hydrogen embrittlement, with no loss in strength or ductility.

A non-affine to affine transition in elasticity occurs with the change of system topology in a packing-derived network, which enables the tuning of elastic moduli and Poisson’s ratio.

The topological nature of the electronic structure of two-dimensional ferromagnetic SrRuO₃ and its relationship to the anomalous Hall effect is explored through transport measurements, angle-resolved photoemission spectroscopy and theoretical modelling.

The Weyl fermions in NdAlSi mediate a helical incommensurate spin density wave, providing a rare example of Weyl-mediated collective phenomena.

Interlayer hybridization in 2D van der Waals materials can change their properties. Here, it is shown that the coupling in CrSBr can be changed from switching the magnetic order from antiferromagnetic to ferromagnetic states.

Tamm plasmon thermal emitters can provide low-cost, efficient mid to long infrared emission, but have been limited by a challenging design. Here the authors apply an inverse design protocol to demonstrate tailorable multi-band emission on CdO films.

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.

Layered clays are of interest for membranes and many other applications but their ion-exchange dynamics remain unexplored in atomically thin materials. Here, using electron microscopy, it is found that the ion diffusion for few-layer two-dimensional clays approaches that of free water and that superlattice cation islands can form in twisted and restacked materials.

Superionic conductors present liquid-like ionic diffusivity with applications ranging from energy storage to thermoelectrics. A two-dimensional type I superionic conductor α-KAg₃Se₂ is now reported and should help to design other materials with tailored ionic conductivities and phase transitions.

Nanostructured birnessite exhibits high specific capacitance and, while an important electrode material for high-power energy storage devices, its capacitive mechanism remains unclear. Capacitive charge storage in birnessite is now shown to be governed by interlayer cation intercalation.

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

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.

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.