Flexible and Wearable Hierarchical MXene/BNC/AgNW Aerogels for Multifunctional Electromechanical and EMI Shielding Applications

The intrinsic self-stacking tendency of MXene severely limits the accessible surface area and impedes the construction of efficient conductive networks, hindering its application in high-performance flexible electronics. To address this issue, we develop a hierarchical MXene/bacterial nanocellulose/silver nanowires (MXene/BNC/AgNWs, denoted as MBA) composite aerogel via liquid-nitrogen-assisted directional freezing. In this system, BNC serves as a robust structural scaffold, while AgNWs act as conductive bridges linking MXene layers, collectively suppressing restacking and facilitating continuous electron transport. The resulting ternary aerogel exhibits a compressive strength of up to 43.93 kPa and demonstrates multifunctional performance. It functions as a sensitive piezoresistive sensor with fast response/recovery times and distinct signal patterns under various human motions. Moreover, the aerogel achieves an electromagnetic interference shielding effectiveness of 37 dB in the X-band (8.2-12.4 GHz) and enables efficient Joule heating with excellent thermal responsiveness and cycling stability. This work offers a promising strategy for designing MXene-based aerogels for applications in flexible sensors, electromagnetic shielding, and integrated thermal management systems.