Discontinuous 3D Printing of Amorphous Photonic Crystal Hydrogels for Multifunctional Applications

Amorphous photonic crystals (APCs) offer angle-independent structural color for reliable sensing, yet their precise 3D fabrication remains challenging due to the tendency of particles to self-assemble into ordered structures. We develop a discontinuous digital light processing 3D printing strategy combining discrete ink reflow and rapid curing to construct disordered APCs hydrogels. The printed hydrogels integrate single-sized polymer nanospheres and MXene nanosheets to achieve structural color, mechanical robustness, and interactive optical/electrical responsiveness. The structural color responds to moisture-induced swelling yet remains unchanged under mechanical deformation because of strain-accommodating microcracks. These features ensure reliable visual feedback without strain interference. Meanwhile, mechanical deformation modulates the conductive network and thus provides a complementary electrical response. In diabetic wound models, the hydrogel enables precise electrical stimulation and provides visual alerts of micro-swelling to prevent secondary damage from unnoticed volumetric changes. This strategy provides a generalizable pathway for precise intervention and real-time monitoring in wound management.