Designing Highly Strain‐Responsive and Recyclable Sensors Via Multilevel Strong and Weak Dynamic Structures Under Low Strain

Abstract Accurate detection of minute external strains is crucial for the development of efficient strain‐responsive sensors. However, designing a recyclable strain‐responsive sensor that simultaneously combines high sensitivity at low strain levels, excellent mechanical properties, and cost‐effectiveness remains a significant challenge. In this study, a strain‐responsive sensor named Cu 2+ ‐crosslinked conductive acrylic resin (PAV/Cu 2+ ‐CB‐x) has been designed by integrating conductive carbon black (CB) into an acrylic resin matrix crossed by Cu 2+ to form a hierarchical dynamic network. Molecular dynamics (MD) simulations reveal that this molecular structure consists of multilevel strong and weak dynamic bonds: weaker coordination bonds and hydrogen bonds endow this sensor with exceptional sensitivity to minor strains, while stronger ionic bonds ensure superior mechanical properties. This meticulous molecular design enables the PAV/Cu 2+ ‐CB‐x to exhibit a tensile strength of 7.16 MPa, an elongation at break of 355.50%, high conductivity of 0.294 S cm −1 , and excellent sensitivity under the strains below 5% (gauge factor = 8.24). Additionally, this PAV/Cu 2+ ‐CB‐x demonstrates a remarkable tensile strength recovery rate of 95.35% after multiple recycling. When applied as a strain‐responsive sensor, it can precisely capture movements of human joints and throat activity. This work provides a promising solution for future applications in motion detection and voice recognition.