Recent Progress of Lithographic Microfabrication by the TPA-Induced Photopolymerization

Several different structures of micro-objects were fabricated by two-photon initiated photopolymerization using newly synthesized chromophore whose structures have been engineered for high two-photon activity. A raster graphics type voxel matrix scanning (VMS) scheme allowed fabrication of two-dimensional (2D) micro-object from a bitmap format figure. Using this technique along with the vacuum pressure discrepancy technique, nano-precision polydimethylsiloxane (PDMS) replica has been fabricated from it original PDMS mold that was originally prepared by two-photon initiated photopolymerization of soft-resin. For better result in photonic crystal fabrication, a quantized-pixel laser writing scheme was employed. A complicated sub-micron 3D photonic lattice was fabricated with high reproducibility. In order to enhance physical/mechanical stability of resulting micro-object, we have tested a new material system which consists of sol-gel precursor and photo-crosslinking of soft-resin. The physical/mechanical stability of micro-object was enhanced greatly by introducing the formation of silica glass interpenetrating network with organic polymer resin.