Direct-write assembly of three-dimensional photonic crystals: Conversion of polymer scaffolds to silicon hollow-woodpile structures

Preparation of 3D Si hollow-woodpile structures that couples direct-write assembly of concentrated polyelectrolyte inks with a sequential silica chemical vapor deposition (CVD) was investigated. The optical properties of the 3D microperiodic woodpiles were characterized after each fabrication step. 3-D microperiodic polymer scaffolds were fabricated in a woodpile architecture via direct-write assembly of a concentrated polyelectrolyte ink. The deposited filaments maintained their cylindrical shape while spanning unsupported regions in the woodpile structure. Results show that the intensity and spectral position of the optical features from polymer woodpile structures depended on the scaffold geometry.