Two-photon-absorbed near-infrared photopolymerization for three-dimensional microfabrication

We present three-dimensional (3-D) microstructures fabricated from photopolymerizable resin with a resolution of 0.62 /spl mu/m. The method used to fabricate such small structures has been developed using a femto-second-pulsed near-infrared (IR) laser. Structures such as microcoils and microtubes are presented which demonstrate the effectiveness of our method. In this method, a two-photon absorption process is successfully utilized to confine the solidification of photopolymerizable resin to the focused spot of the laser, which is possible due to the quadratic dependence of the two-photon absorption rate on light intensity. The experimental system, experimental conditions, and related issues for this novel method of photopolymerization are also discussed.