Fig. 1: Schematic demonstration of the sacrificial-scaffold-mediated TPL process.

The sacrificial scaffold containing a degradable hydrogel network and orderly-arranged nanoparticles is first generated. Then hydrogel precursor is introduced into the scaffold via solvent exchange process, and TPL fabrication was performed. Finally, the hydrogel is immersed in a specific solution to degrade the sacrificial scaffold, leaving the TPL-fabricated hydrogel microstructures with inner nanoparticles.