Electrical Actuation of Coated and Composite Fibers Based on Poly[ethylene-co-(vinyl acetate)]

Robots are typically controlled by electrical signals. Resistive heating is an option to electrically trigger actuation in thermosensitive polymer systems. In this study electrically triggerable polyethylene-co-(vinyl acetate)] (PEVA)-based fiber actuators are realized as composite fibers as well as polymer fibers with conductive coatings. In the coated fibers, the core consists of crosslinked PEVA (cPEVA), while the conductive coating shell is achieved via a dip coating procedure with a coating thickness between 10 and 140 µm. The conductivity of coated fibers σ = 300–550 S m^?1 is much higher than that of the composite fibers σ = 5.5 S m^?1. A voltage (U) of 110 V is required to heat 30 cm of coated fiber to a targeted temperature of ≈ 65 °C for switching in less than a minute. Cyclic electrical actuation investigations reveal ε′_rev = 5 ± 1% reversible change in length for coated fibers. The fabrication of such electro-conductive polymeric actuators is suitable for upscaling so that their application potential as artificial muscles can be explored in future studies.