Wearable Aerogels for Personal Thermal Management and Smart Devices

Maintaining body temperature within safe and comfortable range is crucial; however, thermoregulatory materials face challenges in variable environments and extreme application scenarios. Here, a unique dual air‐gelation strategy is developed to synthesize carbon aerogel nanofiber metafabric for energy‐harvesting thermoregulation. By manipulating polyacrylonitrile/water interaction and charge density of the solution, phase separation and Coulombic repulsion in electrospun jets are promoted, forming curly nanofibers with internal nanopores (size 30–60 nm) that entangle to create nanofibrous dual‐aerogel structure; the carbon aerogel nanofiber metafabric is obtained following pre‐oxidation and optimized graphitization. The resulting metafabric exhibits high elasticity, robust temperature resistance from −196 to 600 °C, exceptional thermal insulation performance, high‐efficiency electrothermal capability (adjustable from 15 to 150 °C), and photothermal property (radiation raised temperature by 22 °C). This work provides rich possibilities to develop advanced carbon nanomaterials for thermal management.

Energy‐Harvesting Carbon Aerogel Nanofiber Metafabric for High‐Efficiency Thermoregulation

Tian,

Chen,

Wang

et al. 2024

Strong and Ultrahigh Temperature‐Resistant Metal Oxide Nanobelt Aerogels

Wang,

Zhang

et al. 2024

Metal oxide aerogels, inorganic cousins of the highly commercialized metalloid oxide silica aerogels, exhibit distinct properties specific to each type. Nevertheless, they share a common challenge with silica aerogels—brittleness and low mechanical strength due to their particulate necklace‐like structure. In contrast, polymer aerogels often boast significantly enhanced mechanical properties thanks to their nanofibrillated networks. To enhance the mechanical properties of metal oxide aerogels, the metal oxide formation with a polymeric nanostructure is micro‐templated. This method transforms the necklace‐like particulate microstructure of metal oxide aerogels (e.g., Al2O3 Cr2O3, and Fe2O3) into a polymer‐like nanobelt structure. Remarkably, even after removing the polymer template through calcination at 600 °C, the nanobelt structure remains intact. These metal oxide nanobelt (MNB) aerogels exhibit exceptional compressibility while retaining their mesoporous structure. As a demonstration, the resulting Al‐MNB aerogel can withstand compression up to 80% strain without fracturing while preserving its porous nanobelt structure and a high specific surface area of 228 m2 g−1 and a pore volume of 0.7 cm3 g−1 after heat treatment at 1300 °C. This work introduces an innovative strategy for creating a distinctive polymer‐like nanobelt microstructure, paving the way for novel applications of metal oxide aerogels with unique structures and enhanced performance.

Highly Stretchable Supercapacitor‐Type Multifunctional Self‐Powered Porous Electronic Skins

Zhang,

Wang,

Liang

et al. 2024

The development of highly stretchable self‐powered electronic skins with a broad detection range is urgently needed but remains a great challenge. Herein, unprecedented highly stretchable, broad‐range‐response, supercapacitor‐type, one‐body, and self‐powered electronic skins are developed by assembling porous polyurethane/polypyrrole electrode, polyacrylic acid/polyacrylamide ionic gel electrolyte, and porous polyurethane/MXene electrode. The folded porous structure of the electrodes significantly enhances the stretchability, while the modulus‐gradient multilayer structure of the device effectively broadens the pressure detection range. The electronic skins combine self‐powered dynamic/static pressure sensing, ultrabroad detection range (20 Pa–3.5 MPa), ultrahigh stretchability up to 387%, excellent compression stability (5000 cycles under 195 kPa), and good stretching stability (500 cycles under 200% tensile strain). They have the capability of monitoring human body motions, physiological signals, and high pressures from motorcycle tires, as well as tactile sensing of robotic grippers. In addition, they can be applied for highly stretchable thermal management and electromagnetic shielding devices. This work provides a new strategy for the development of highly stretchable, broad‐range‐response, and multifunctional self‐powered wearable electronics and sensors.