Three-dimensional (3D) microstructures are essential elements in various technological applications, including optical coatings, [ 1 , 2 ] tissue engineering scaffolds, [ 3 ] microfl uidics, [ 4 ] energy storage devices, [ 5 , 6 ] plasmonics, [ 7 ] and photonic crystals. [ 8 , 9 ] While conventional methods, such as photo lithography and electron beam lithography, are costly and ineffective in ...