Multifunctional Flexible AgNW/MXene/PDMS Composite Films for Efficient Electromagnetic Interference Shielding and Strain Sensing

With the rapid development of electronic information technology, composite materials with outstanding performance in terms of electromagnetic interference (EMI) shielding and strain sensing are crucial for next-generation smart wearable electronic devices. However, the fabrication of flexible composite films with dual functionality remains a significant challenge. Herein, multifunctional flexible composite films with exciting EMI shielding and strain sensing properties were constructed using a facile vacuum-assisted filtration process and transfer method. The films consisted of ultrathin AgNW/MXene (Ti3C2Tx)/AgNW conductive networks (1 μm) attached to a flexible polydimethylsiloxane (PDMS) substrate. The obtained AgNW/MXene/PDMS composite film exhibited an exceptional EMI shielding effectiveness of 50.82 dB and good flexibility (retaining 93.67 and 90.18% of its original value after 1000 bending and stretching cycles, respectively), which are attributed to the enhanced multilayer internal reflection network created by the AgNWs and MXene as well as the synergistic effect of PDMS. Besides EMI shielding, the composite films also displayed remarkable strain sensing properties. They exhibited a wide linear range of tensile strain up to 68% with a gauge factor of 468. They also showed fast response, ultralow detection limit, and high mechanical stability. Interestingly, the composite films could also detect motion and voice recognition, demonstrating their potential as wearable sensors. This study highlights the effectiveness of multifunctional flexible AgNW/MXene/PDMS composite films in resisting electromagnetic radiation and monitoring human motion, thereby providing a promising solution for the development of flexible wearable electronic devices in complex electromagnetic environments.