Research Trends on Silk-Based Conductive Fibers with the Enhanced Machine Washability by Adopting PEDOT:PSS

With the advance in wearable electronics, there is increasing demand for conductive fibers that are stable under machine washing. Silk-based conductive fibers in particular have attracted significant attention due to their biocompatibility and excellent mechanical properties. To achieve the machine washability of silk-based conductive fibers, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) has been adopted as a conductive functional layer. PEDOT:PSS with ethylene glycol has a negative surface charge that can strongly adhere to the positively charged silk surface, leading to the excellent machine washability of silk-based conductive fibers. Various types of PEDOT:PSS/silk-based conductive fibers have been demonstrated in past research, including those in which different types of materials, such as silver (Ag) nanowires, carbon nanotubes, or manganese dioxide (MnO2), have been inserted to produce a range of electrical and chemical properties that can be used for different applications. In this mini-review, strategies to enhance the stability of silk-based conductive fibers using PEDOT:PSS are discussed. Various types of PEDOT:PSS/silk-based conductive fiber are introduced and research trends and future research directions are discussed.