A sustainable pathway toward high-performance sodium alginate flexible sensors based on wool keratin-mediated carbon nanotube dispersions

Recently, flexible wearable electronic devices have attracted extensive attention as an alternative to traditional rigid metallic conductors in the fields of personal health monitoring, human motion tracking, and biomimetic skin, due to their unique properties. However, most current wearable sensing devices are generally limited by poor sensitivity, limited detection range, and the inability to integrate well with clothing. In this paper, a hydrogen-bonded crosslinked network based on sodium alginate (SA) and wool keratin (WK) non-covalently modified carbon nanotubes (CNTs) was rationally designed and fabricated into a flexible pressure sensor named as SA&WK/CNT sensor. The resulting sensor is capable of accurately detecting the motion of various joints, with a fast response time of 0.15 s, a high sensitivity of 4.32 kPa −1 , and an excellent strength of 17.57 MPa. Moreover, the SA1WK2/CNT15@fabric flexible sensor, prepared by combining plain weave fabric with SA1WK2/CNT15 composite, exhibits enhanced sensitivity of 13.33 kPa −1 . Notably, the flexible sensor demonstrates outstanding performance in practical applications, including handwriting recognition and precise motion detection. This work not only reveals the inherent piezoresistive excellence of protein-based flexible films but also establishes a novel paradigm for developing high-performance fabric sensors through synergistic integration with textile substrates, paving the way for wool keratin-based materials in next-generation wearable technologies and smart health monitoring systems.