Environmentally friendly melt-spinning of polyurethane fibers modified with polylactic acid and silicone for healthcare applications

With concern over the environment increasingly important globally, there is an imperative for the development of more sustainable electronic materials. Flexible strain sensors, capable of translating mechanical deformation into electrical signals, have garnered significant interest in applications such as healthcare monitoring and soft robotics. In this study, a biodegradable fiber-based flexible strain sensor with excellent electromechanical properties was developed using custom polyurethanes modified with polylactic acid and silicone (Si-BTPU) blended with carbon nanotubes (CNTs) via environmentally friendly melt spinning technology. The results revealed that the Si-BTPU exhibited biodegradability, with a degradation rate of 5.7 % after just 4 weeks. Notably, the obtained strain sensor demonstrated an impressive sensing range of 0–395 %, high sensitivity (gauge factor GF = 42) and a low detection limit of less than 2 %, while maintaining stable electromechanical performance over 10,000 tensile loading-unloading cycles. Furthermore, human epidermal fibroblasts (HDFs) displayed strong adhesion to and proliferation on the strain sensor, indicating its suitability for skin surface applications. This research provides valuable insights into the advancement of wearable electronic devices for healthcare monitoring within the realm of advanced materials.