DLP-Printable Hydrogel with Integrated Tear Resistance and Low Hysteresis for Flexible Strain Sensing

Hydrogel has become an ideal material for flexible wearable devices due to its flexibility and ductility. Hydrogels, by modulating the polymer network, have demonstrated various properties essential for strain sensing, including low-temperature resistance, tear resistance, and high sensitivity. Despite these advances, breakthroughs in achieving both low hysteresis and high tear resistance simultaneously remain limited. This study introduces a novel hydrophobic associating hydrogel, synthesized via photoinitiated polymerization of acrylamide (AAM) and dodecyl methacrylate (LMA). The tear resistance provided by the poly-LMA micelles resulted in a gel elongation of 1500% under notched conditions. The hydration of CaCl2 altered the distribution of hydrogen bonds and chain segments in the polymer network, and the cyclic dissipation energy of the low hysteresis gel was only 15 kJ·m–3. Utilizing digital light processing (DLP) 3D printing, the hydrogel was rapidly fabricated into complex structures, demonstrating excellent performance in flexible strain sensing applications. This approach offers a streamlined solution for developing next-generation flexible strain sensing materials, combining advanced material design with innovative fabrication techniques.