We report a facile method to fabricate free-standing, 3D hydrogel microarchitectures of chemically sol-gel transitional hydrogels, which is based on the use of hydrophilic substrate and aerosol of gelling agent without molding (or sandwiching) process. Using proposed methods, we fabricated hydrogel microarchitectures of sheets, meshes, or microunits without morphological distortions on the microscale. These hydrogel microarchitectures could be easily and stably exfoliated from the substrates and cultured (in the case of containing cells). These free-standing hydrogel microarchitectures in sheets, meshes, or microunits can be easily harvested and assembled as a biofabrication unit to generate complex composites with controlled microscale structures.