Unipolar coiled CNT yarn artificial muscles with bio-friendly polyelectrolytes for smart textiles

We report bio-friendly, solid-state artificial muscles based on coiled CNT yarns coated with ion-selective polyelectrolyte. Operating in air at low voltages, the resulting actuators demonstrate unipolar behavior with actuation over the entire electrochemical window, strain around 3% and work density of 120 kJ m⁻³ while maintaining stability over hundreds of cycles. The actuators integrate readily into textile structures via inlaying without loss of performance. The combination of commercial CNT yarns, DES-based electrolytes, and scalable fabrication offers a promising route toward wearable artificial muscles for soft robotics and smart textiles