Aerogel-based composites hold promising application prospects as potential electromagnetic wave (EMW) absorption materials, yet the construction of such materials with ingenious microstructures, appropriate magnetic/dielectric multi-components, and integrated multifunctionality remains considerably challenging. Herein, a multicomponent Co/MnO/Ti₃C₂T_x MXene/rGO (CMMG) hybrid aerogel featured with three-dimensional (3D) vertical directional channel architecture is reported. Benefiting from the synergistic effect arising from the 3D conductive networking structure, diverse heterogeneous interfaces, magnetic/dielectric multicomponent, and multiple loss pathways, the optimized CMMG-2 aerogel delivers fascinating EMW absorption capabilities, characterized by a minimal reflection loss (RL_min) of −77.41 dB and an effective absorption bandwidth (EAB) of 6.56 GHz. Additionally, the remarkable hydrophobicity, exceptional thermal insulation capabilities, and outstanding photothermal properties of CMMG-2 aerogel make it highly promising for multiple application in diverse and demanding environments. Interestingly, the distinctive pore structure of hybrid aerogel also allows it for sensitive and reliable detection of electrical signals caused by pressure changes and human motion. Thus, this research provides a viable design strategy for the development of lightweight, efficient, and multifunctional aerogel-based EMW absorption materials for various application scenarios.

With the capability of interconversion between electrical and mechanical energy, piezoelectric materials have been revolutionized by the implementation of perovskite-piezoelectric-ceramic-based studies over 70 years. In particular, the market of piezoelectric ceramics has been dominated by lead zirconate titanate for decades. Nowadays, the research on piezoelectric ceramics is largely driven by cutting-edge technological demand as well as the consideration of a sustainable society. Hence, environmental-friendly lead-free piezoelectric materials have emerged to replace lead-based Pb(Zr,Ti)O₃ (PZT) compositions. Owing to the inherent high mechanical quality factor (Q_m) and low energy loss, (Li,Na)NbO₃ (LNN) materials have recently drawn increasing attention and brought advantages to high-power piezoelectric applications. Although the crystallographic structures of LNN materials were intensively investigated for decades, the technical strategies for electrical performance are still limited. As a result, the property enhancement appears to have approached a plateau. This review traces the progress in the development of LNN materials, starting from the polymorphism in terms of the crystal structures, phase transitions, and local structural distortions. Then, the key milestone works on the functional tunability of LNN are reviewed with emphasis on involved engineering approaches. The exceptional performance at a large vibration velocity makes LNN ceramics promising for high-power applications, such as ultrasonic welding (UW) and ultrasonic osteotomes (UOs). The remaining challenges and some strategic insights for synergistically engineering the functional performance of LNN piezoceramics are also suggested.