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Highly stretchable aerogel films are attractive for advanced next‐generation stretchable electronics. However, it is a great challenge to achieve high stretchability for aerogel films. Here, several types of unprecedented ultra‐stretchable semiconducting polymer‐based aerogel films with crimpled porous structures are developed via crosslinking and template methods combined with uniaxial and biaxial pre‐stretching strategies. The semiconducting aerogel films obtained by uniaxial pre‐stretching exhibit ultrahigh stretchability up to 100–200%, while those obtained by biaxial pre‐stretching show high biaxial stretchability up to 50%. The resulting aerogel films show strain‐insensitive electrical and joule heating properties. A prototype of the aerogel film‐based stretchable organic electrochemical transistor (OECT) is developed for the first time. Benefiting from their unique porous structures, the aerogel film‐based OECTs exhibit enhanced on/off ratio and transconductance compared with corresponding dense film‐based OECTs, high stretchability up to 100%, and high stretching stability with 10 000 stretching cycles under 30% strain. It is demonstrated that the aerogel film‐based OECTs can be applied as high‐performance stretchable artificial synapses and biosensors. This work gives a versatile strategy toward highly stretchable aerogel films promising for flexible electronics. [ABSTRACT FROM AUTHOR]

Super304H steel, imbued with trace amounts of TiC/TiB2 nano-particles, was fabricated to assess the influence of nano-particles on its creep properties under the condition of 600 °C/330 MPa. Our findings elucidate that the inclusion of trace TiC/TiB2 led to a 21% improvement in the creep life of Super304H steel, while diminishing the creep rate from 6.6 × 10−5 h−1 to 5.7 × 10−5 h−1. The synergistic precipitation strengthening of the nano-scale Cu-rich phases, needle-like M23C6 phases, and NbN phases was primarily responsible for this exceptional creep resistance. During the long-term creep process, the nano-scale Cu-rich phase was very stable with little change. In the Super304H steel, M23C6 and NbN phases had a non-coherent interface and an orientation relationship of 001 NbN // 001 M 23 C 6 . M23C6 and NbN phases in the Super304H steel incorporating minute TiC/TiB2 nano-particles also had a non-coherent interface but a 1 - 10 NbN // 2 - 33 M 23 C 6 orientation relationship. The M23C6 and NbN phases effectively impede the dislocation movement and were shown to increase the creep strength considerably. [ABSTRACT FROM AUTHOR]

MXene‐based aerogels are promising candidates for wearable electronics due to their unique structures and properties. However, the reported MXene‐based aerogels show poor stretchability, significantly restricting their applications in wearable electronics. Herein, unprecedented highly stretchable MXene‐based aerogels with crimpled and reentrant microstructures are developed via synergistic assembly of MXene and flexible polymers combined with uniaxial and biaxial hot‐pressing strategies. The uniaxially hot‐pressed MXene‐based meta‐aerogels show compressed and crimpled microstructures and combine ultrahigh stretchability up to 427%, high elasticity, high compressibility, high fatigue resistance upon compression and stretching, and near‐zero Poisson's ratios. The biaxially hot‐pressed MXene‐based meta‐aerogels exhibit reentrant microstructures and achieve high stretchability and negative Poisson's ratios upon stretching in different directions, which have never been realized by traditional aerogels. It is demonstrated that they can be used for ultrabroad‐range pressure/strain sensors, highly stretchable triboelectric nanogenerators, and smart thermal management with tunable thermal insulation and Joule heating performances achieved by stretching. This work opens a new way to highly stretchable aerogels with near‐zero and negative Poisson's ratios promising in wearable electronics, nanogenerators, thermal management, energy storage, etc. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) possess low operating voltage and excellent amplification capability and show promising applications in biosensors and flexible electronics. However, the active layers of OECTs are usually dense films, which show limited ion penetration/transport, resulting in limited performances of OECTs. Here, unprecedented high‐performance flexible multifunctional OECTs based on nanoporous (mainly 2–60 nm), high‐specific‐surface‐area (255–281 m2 g−1), and flexible conjugated polymer aerogel films are developed. The nanoporous structures effectively facilitate ion penetration/transport, leading to significantly enhanced transconductance (48.5–53.5 mS) and on/off ratio (6.4 × 104) of the OECTs compared with those of dense devices. The resulting OECT‐based glucose sensors exhibit an ultralow detection limit of 1 pm, approximately two to three orders of magnitude lower than those of the previously reported OECT glucose sensors, and an ultrabroad detection range of 1 pm–5 m. They can detect trace amounts of glucose in sweat, serum, saliva, and urine in real time. Moreover, the OECTs can be used for high‐performance flexible artificial synapses and electrocardiogram monitoring. This work provides a powerful strategy toward highly sensitive biosensors, artificial synapses, and electrophysiological signal monitoring. [ABSTRACT FROM AUTHOR]

With the increasing demands for artificial intelligence, robotics, electronic skin, healthcare, and energy storage/conversion, the research focus on flexible electronics has started to shift from being merely bendable and rollable to being stretchable. In recent years, stretchable aerogels and foams have drawn significant attention in the field of flexible electronics due to their unique porous structures, low density, high porosity, and high flexibility. This work provides a comprehensive review of the state‐of‐the‐art developments in stretchable aerogels and foams, encompassing their preparation, structures, properties, and applications. The preparation methods, typical structures of stretchable aerogels and foams, stretching principle, and the relationship between their structures, stretchability, and other properties are investigated. Their latest applications in stretchable strain/pressure sensors, electrodes and conductors, chemical sensors and biosensors, supercapacitors, batteries, triboelectric nanogenerators, electromagnetic shielding, microwave absorption, thermal management, adsorption, separation/filtration, and shape memory are introduced. Furthermore, the challenges and opportunities of stretchable aerogels and foams are summarized. This work provides a guideline for the development of stretchable aerogels and foams and next‐generation high‐performance flexible electronics based on stretchable porous materials. [ABSTRACT FROM AUTHOR]