Hygroscopic MXene/Protein Nanocomposite Fibers Enabling Highly Stretchable, Antifreezing, Repairable, and Degradable Skin-Like Wearable Electronics

Wearable devices made of degradable fibers are rising stars in smart healthcare by virtue of their light weight, flexibility, and weavability. Silk protein is one promising platform for ideal fiber-type electronic devices due to its inherent biocompatibility and biodegradability. However, it remains a challenge for conductive silk-based fiber electronics to achieve high stretchability and skin-like softness. Here, hygroscopic calcium-modified MXene/silk nanocomposite fibers (Ca@MSNFs) are fabricated by decorating the wet-spun MXene/silk fibers with hygroscopic CaCl 2, exhibiting 3.2 g g –1 water capture capacity at 90% relative humidity (RH), high stretchability (279.9%), degradability, repairability, and freeze-resistance (−18 °C). Furthermore, the Ca@MSNFs are assembled as humidity/strain sensors to monitor respiratory signals and body movements, showing great promise for the diagnosis of apnea syndrome and rehabilitation training. Moreover, Ca@MSNFs are degradable and do not cause pollution or environmental damage. Therefore, this work offers a promising strategy for constructing stretchable and degradable electronic devices for advanced healthcare applications.