Graphene has an extremely high in-plane strength yet considerable out-of-plane softness. High crystalline order of graphene assemblies is desired to utilize their in-plane properties, however, challenged by the easy formation of chaotic wrinkles for the intrinsic softness. Here, we find an intercalation modulated plasticization phenomenon, present a continuous plasticization stretching method to regulate spontaneous wrinkles of graphene sheets into crystalline orders, and fabricate continuous graphene papers with a high Hermans’ order of 0.93. The crystalline graphene paper exhibits superior mechanical (tensile strength of 1.1 GPa, stiffness of 62.8 GPa) and conductive properties (electrical conductivity of 1.1 × 10⁵ S m⁻¹, thermal conductivity of 109.11 W m⁻¹K⁻¹). We extend the ultrastrong graphene papers to the realistic laminated composites and achieve high strength combining with attractive conductive and electromagnetic shielding performance. The intercalation modulated plasticity is revealed as a vital state of graphene assemblies, contributing to their industrial processing as metals and plastics.

Reversible fiber fusion and fission: Materials that can cycle between states are of interest for actuators, soft robotics, or recoverable membranes for separations. Chang et al. show that a collection of graphene oxide fibers can fuse into a single stronger fiber upon immersion in a solvent, extraction, and drying under tension (see the Perspective by Cruz-Silva and Elías). The geometrical deformation of the fibers during drying and swelling plays an important role in the reversible cycles, with a large volume change between the dried and swelled fibers. Moreover, fibers made from polymers, glass, metal, or silk can be given these abilities when coated with a micron-sized layer of graphene oxide. Science , this issue p. 614 ; see also p. 573

In this work, we perform molecular dynamics (MD) simulations to study the effect of rippling on the Poisson's ratio of graphene. Due to the atomic scale thickness of graphene, out-of-plane ripples are generated in free standing graphene with topological defects (e.g. heptagons and pentagons) to release the in-plane deformation energy. Through MD simulations, we have found that the Poisson's ratio of rippled graphene decreases upon increasing its aspect ratio η (amplitude over wavelength). For the rippled graphene sheet η = 0.188, a negative Poisson's ratio of −0.38 is observed for a tensile strain up to 8%, while the Poisson's ratio for η = 0.066 is almost zero. During uniaxial tension, the ripples gradually become flat, thus the Poisson's ratio of rippled graphene is determined by the competing factors of the intrinsic positive Poisson's ratio of graphene and the negative Poisson's ratio due to the de-wrinkling effect. Besides, the rippled graphene exhibits excellent fracture strength and toughness. With the combination of its auxetic and excellent mechanical properties, rippled graphene may possess potential for application in nano-devices and nanomaterials.

Aerogels are known for their high porosity and very low density and can be made from a range of materials, but are limited by structural instability under extreme thermomechanical conditions. We report on 194 types of dome-celled ultralight aerogels that maintain superior elasticity spanning from 4.2 kelvin (K) to 2273 K, realized by a two-dimensional channel–confined chemistry method. Such aerogels exhibit superelasticity under 99% strain for 20,000 cycles and thermal shock resistance at 2273 K over 100 cycles. The high-entropy carbide aerogel achieves a thermal conductivity of 53.4 mW·m ⁻¹ ·K ⁻¹ at 1273 K and 171.1 mW·m ⁻¹ ·K ⁻¹ at 2273 K. The combination of temperature-invariant elasticity and chemical diversity makes such aerogels highly promising for extreme thermomechanics, from heat-insulated industries to deep space exploration.

The article presents a systematic framework to evaluate and improve the energy efficiency of mobile soft robots.