SU-8 for real three-dimensional subdiffraction-limit two-photon microfabrication

We report the inherent utility of two-photon-absorption (TPA) in the fabrication of real three-dimensional (3D) structures with subdiffraction-limit resolution, based on SU-8 as the threshold polymer media. We exploit the nonlinear velocity dependence of TPA photopolymerization as the shutter mechanism for disruptive 3D lithography. We show that low numerical aperture optics can be used for the rapid microfabrication of ultrahigh-aspect ratio photoplastic pillars, planes, and cage structures. (C) 2004 American Institute of Physics.