Self-Healing Conductive Hydrogel Based on a Schiff Base Bond for Digital Light Processing 3D Printing

The digital light processing (DLP) 3D printing technology enables the construction of hydrogels with high precision and complex structures. In this work, a hydrogel precursor solution with excellent printing performance was developed through a chemical and physical dual cross-linking strategy. The printed poly(acrylamide–acrylic acid)/N,N′-bis(vanillinidene)ethylenediamine1–carbomer1 (P(AM–AA)/N,N′-BVE1–CBM1) hydrogel exhibited excellent tensile strain (685%), tensile strength (0.37 MPa), Young's modulus (157 kPa), and toughness (1075 kJ/m3), as well as good adhesion properties and self-healing ability. Notably, its shape memory properties enable it to recover quickly after deformation and show excellent strain response characteristics, enabling reliable and stable conversion of human motion into electrical signals, and it is very suitable as a flexible sensor for monitoring human body motion. With remarkable precision and customization ability to fabricate unique structures and excellent response behavior, the P(AM–AA)/N,N′-BVE1–CBM1 hydrogel based on DLP 3D printing is promising in the field of personalized wearable flexible sensors.