Introduction . Complex three-dimensional (3D) micro- and nanostructures provide key functions in systems with various sizes and functions, which range from the organs of living organisms to microscale devices (e.g., foldable microelectronics1, deformable batteries2, and bioelectronics3 , 4) and nanoscale devices (e.g., chemical/physical sensors5 , 6, surface-enhanced Raman spectroscopic substrates7, and holographic displays8). Therefore, methods fo...