Sulfur‐ and Nitrogen‐Rich Porous π‐Conjugated COFs as Stable Electrode Materials for Electro‐Ionic Soft Actuators

Abstract An unprecedented type of electronically conjugated porous covalent organic framework (COF) is synthesized for specific use in the electrode materials of electro‐ionic soft actuators. Because the basic structure contains most of the electron‐rich nucleophilic heteroatoms found in the periodic table with high percentages (13.84% for sulfur, 13.97% for nitrogen, and 19% for oxygen), adding only a small amount of these COFs (4.0 wt%) to poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT‐PSS) increases the specific capacitance by 380%, resulting in a significant improvement of the actuation performance without any back‐relaxation. In comparison with pure PEDOT‐PSS electrodes, the COFs‐based actuators show a 280% shorter phase delay, 350% faster rise time, 290% higher bending displacement, 320% stronger blocking force, and ultralong durability up to 20 000 cycles of continuous actuation. These impressive improvements in performance enable the realization of a soft touch finger for confidently opening folders and swiping pages on a fragile smartphone device. While the application of these COFs in actuators can contribute to the progress of ionic soft actuators and realization of soft robotics, these COFs can be employed directly or modified for use in numerous fields, such as electro‐ or photocatalysts, sensors, and optoelectronics.