Flexible and breathable 3D porous SSE/MXene foam towards impact/electromagnetic interference/bacteria multiple protection performance for intelligent wearable devices

As intelligent wearable devices, they will inevitably be subjected to various damages and disturbances from the external environment during daily use. Therefore, it is urgent to develop safeguarding materials with multiple protective properties. Herein, this work developed a flexible and breathable three-dimensional (3D) porous shear stiffening elastomer (SSE)/MXene (M-SSE) foam with impact/electromagnetic interference (EMI)/bacteria multiple protection performance for intelligent wearable devices. The continuous conductive MXene network in the 3D SSE porous structure made M-SSE foam exhibit excellent electromagnetic interference shielding property with a high shielding effectiveness of 34 dB. Attributed to the shear stiffening effect of porous SSE matrix, M-SSE foam possessed unique anti-impact and protection properties. The energy dissipation rate reached up to more than 85%, illustrating M-SSE foam could effectively attenuate the external impact force and absorb the impact energy. Inherited from the excellent photothermal performance of MXene, M-SSE foam achieved a considerable saturated temperature of 98 °C under 0.57 W/cm² laser power. Therefore, M-SSE foam showed extraordinary antimicrobial property for Staphylococcus aureus according to the principle of photothermal sterilization. Finally, for the development of intelligent wearable devices, conductive M-SSE foam could be used as an intelligent sensor to monitor various human movements owing to the highly sensitive property. This work greatly expanded the application prospect of multifunctional protective materials in various complex environments and promoted the development of multifunctional smart wearable devices in protection field.