An Environment-Tolerant, Reprocessable, and Self-Healable Ionogel with High Performance Retention for Reliable Sensing

The surging need for ionic sensors has sparked the development of superior ionogels. Past iterations of ionogels, however, have faltered in concurrently achieving robust solvent resistance, potent self-healing, and excellent postrecycling performance retention, restricting their utility in corrosive or damaging environments. This research details the synthesis of an advanced ionogel via the one-step polymerization of acrylamide and acrylic acid in 1-butyl-3-methylimidazolium chloride, catalyzed by tannic acid (TA) and iron ions. The ionogel is characterized by plentiful noncovalent bonds and partial TA-bound iron ion stabilization, yielding exceptional adhesive properties (reaching 477 kPa with copper at room temperature and 1.93 MPa with aluminum at −20 °C), significant solvent resistance (with less than 5% weight increase and retained mechanical and adhesive performance after organic solvent immersion), superior self-healing (up to 99.4%), and optimal recyclability (with lap-shear strength and tensile strength revitalized to 95 and 98%, respectively, after a single recovery cycle). Strain sensors based on this ionogel remain stable after posthealing or organic solvent immersion. Wearables utilizing the ionogel are capable of monitoring and differentiating varied human motions. This study is poised to broaden design approaches for creating sophisticated industrial robots and wearable devices.