Improving spatial resolution of two-photon microfabrication by using photoinitiator with high initiating efficiency

The lateral spatial resolution (LSR) in two-photon induced polymerization was improved to 80 nm by using an anthracene derivative (9,10-bis-pentyloxy-2,7-bis[2-(4-dimethylamino-phenyl)-vinyl]anthracene (BPDPA)) as a highly sensitive and efficient photoinitiator. Photocurable resin containing 0.18 mol % BPDPA exhibited a low polymerization threshold of 0.64 mW at 800 nm. Theoretical calculations showed that the LSR can be increased by reducing the laser power, indicating that the LSR could be improved using more sensitive initiators in the future. (c) 2007 American Institute of Physics.