Preparation and performance of self-cleaning photothermal-induced self-healing flexible sensors

Abstract

Flexible conductive materials for wearable applications have seen remarkable advancements in recent years. However, a significant challenge that must be addressed is their susceptibility to accidental mechanical damage. In this study, a self-healing superhydrophobic flexible fabric sensor by incorporating fluorinated polyurethane with fluorinated side chains and graphene modified with Fe3O4 nanoparticles. The fabric composite coating exhibited excellent hydrophobicity and self-cleaning ability, allowing easy removal of dirt and dust by rainwater or other liquids. Due to its excellent conductivity and stretch recovery properties, the composite coating can be applied as a wearable fabric sensor. The sensor demonstrates remarkable sensitivity to strain and can be used to monitor the movements of fingers, wrists, elbows, and other joints. Most importantly, the damaged fabric coating could restore surface integrity, repair conductivity, and maintain superhydrophobicity, which is attributed to the dynamic reversible nature of disulfide bonds and the induced dipole polarization effect of fluorinated side chains. Moreover, the fabric sensor exhibits stable photothermal conversion performance based on the joint effect of graphene and Fe3O4. This property provides a foundation for light-induced self-healing. The combination of a fluorine-modified self-healing polyurethane, Fe3O4 nanoparticles-modified graphene (FFNs-iaG), and an elastic fabric creates a self-healing superhydrophobic conductive fabric coating. This coating has excellent properties for various applications, enhancing the longevity and reliability of the fabric sensor. The combination of these materials greatly improves the performance of the fabric composite coating, resulting in a versatile fabric sensor with unique characteristics suitable for a wide range of applications.