Biocompatible Polylactic Acid/Wool Keratin/Carbon Nanotubes Fibers via Electrospinning as a Flexible Pressure Electronic Sensor

The extraction of wool keratin protein (WK) from wool waste has garnered attention for its potential application in tissue engineering, drug delivery, and flexible pressure sensors, contributing to the efficient utilization of waste wool. Herein, we utilized biobased polylactic acid (PLA) as the polymer for electrospinning and incorporated carbon nanotubes (CNTs) as conductive additives in the electrospinning solution. WK, extracted from waste wool via a reduction method, exhibited excellent dispersibility and stability of carbon nanotubes in the spinning solution, enabling the preparation of a highly sensitive resistive flexible pressure sensor. The results demonstrate that the PLA/WK/CNTs @CNTs flexible pressure sensor exhibits a high sensitivity of 12.64 kPa–1 and a fast response/recovery time of 63 ms. Moreover, it possesses the lowest detection limit of 5.64 Pa, excellent stability over 6000 cycles, and good linearity within a wide working range (0–30 kPa), making it suitable for wearable biometric monitoring applications such as finger pressure, finger bending, and pulse monitoring, as well as visual interaction such as interactive blankets for infants. Therefore, we propose a high-quality wool waste utilization scheme, showcasing the potential application of discarded wool in smart living.