An efficient two-photon-generated photoacid applied to positive-tone 3D microfabrication.
A two-photon-activatable photoacid generator, based on a bis[(diarylamino) styryl]benzene core with covalently attached sulfonium moieties, has been synthesized. The photoacid generator has both a large two-photon absorption cross section (delta = 690 x 10(-50) centimeter(4) second per photon) and a high quantum yield for the photochemical generation of acid (phiH+ = 0.5). Under near-infrared laser irradiation, the molecule produces acid after two-photon excitation and initiates the polymerization of epoxides at an incident intensity that is one to two orders of magnitude lower than that needed for conventional ultraviolet-sensitive initiators. This photoacid generator was used in conjunction with a positive-tone chemically amplified resist for the fabrication of a three-dimensional (3D) microchannel structure.
Zhou
Wenhui
W
Department of Chemistry, Optical Sciences Center, University of Arizona, Tucson, AZ 85721, USA.
Kuebler
Stephen M
SM
Braun
Kevin L
KL
Yu
Tianyue
T
Cammack
J Kevin
JK
Ober
Christopher K
CK
Perry
Joseph W
JW
Marder
Seth R
SR