Direct foaming from solids is the most efficient method to fabricate porous materials. However, the ideal foaming fails to prepare aerogel of nanoparticles because the plasticity of their solids is denied by the overwhelming interface interactions. Here, we invent a hydroplastic foaming method to directly convert graphene oxide solids into aerogel bulks and microarrays, replacing the prevalent freezing method. The water intercalation plasticizes graphene oxide solids and enables direct foaming instead of catastrophic fragmentation. The bubble formation follows a general crystallization rule and allows nanometer-precision control of cellular wall thickness down to 8 nm. Bubble clustering generates hyperboloid structures with seamless basal connection and renders graphene aerogels with ultrarobust mechanical stability against extreme deformations. We exploit graphene aerogel to fabricate tactile microarray sensors with ultrasensitivity and ultrastability, achieving a high accuracy (80%) in artificially intelligent touch identification that outperforms human fingers (30%).

A rapid and high-yield (up to 85%) preparation of a zwitterionic chitin nanofiber (DE-CO-ChNF) has been demonstrated.

Nitrogen-enriched (N-enriched) carbon nanofiber aerogels (NCNAs) with an ultrafine nanofiber network structure were designed and prepared by using chitin nanofiber aerogels as the precursor. Because of the uniform nanofibrous architecture and nitrogen-rich composition of chitin nanofiber aerogels, the NCNAs exhibited large specific surface area (490–1597 m2 g–1) and a high nitrogen content (2.07–7.65%). As a consequence, supercapacitor electrodes prepared from NCNA-900 showed specific capacitances as high as 221 F g–1 at the current density of 1.0 A g–1 and good capacitance retention of 92% over 8000 cycles in a 6.0 mol L–1 KOH electrolyte without further activation. Moreover, the NCNA-900 could also be applied as an effective adsorbent for dye adsorption, such as Congo red (496 mg g–1) and Rhodanine B (489 mg g–1). In view of an excellent electrochemical performance and high adsorption capacities for dyes as well as cost-effective and eco-friendly approaches, NCNAs derived from marine chitin show great potential for application in energy storage and environmental remediation.

Atomically thin 2D graphene sheets exhibit unparalleled in‐plane stiffness and large out‐of‐plane elasticity, thereby providing strong mechanical resonance for nanomechanical devices. The exceptional resonance behavior of ultrathin graphene, which promises the fabrication of superior acoustic absorption materials, however, remains unfulfilled for the lack of applicable form and assembly methods. Here, a highly efficient acoustic absorber is presented, wherein cellular networks of ultrathin graphene membranes are constructed into polymer foams. The ultrathin graphene drums exhibit strong resonances and efficiently dissipate sound waves in a broad frequency range. A record specific noise reduction coefficient (51.3 at 30 mm) is achieved in the graphene‐based acoustic absorber, fully realizing the superior resonance properties of graphene sheets. The scalable method facilely transforms commercial polymer foams to superior acoustic absorbers with a ≈320% enhancement in average absorption coefficient across wide frequencies from 200 to 6000 Hz. The graphene acoustic absorber offers a convenient method to exploit the extraordinary resonance properties of 2D sheets, opening extensive new applications in noise protection, building design, instruments and acoustic devices.