Multi-wavelength volumetric lithography

Abstract

Modern Two-Photon Lithography (TPL) is a golden standard among various 3D micro- and nano-fabrication techniques. The two-photon absorption phenomenon allows to selectively initiate the polymerization reaction in different points in 3D space, enabling accurate point-by-point 3D. TPL has a well-known constraint, the limited speed of printing related to the time it takes to scan a volume by a focused femtosecond laser beam. The inherent need for extremely high illumination intensity required for initiation of the polymerization reaction poses a fundamental problem. We are developing an alternative 3D printing technique based on a multi-wavelength polymerization process that requires orders of magnitude lower illumination intensities while still allowing localization of the polymerization reaction in 3D space. Multi-wavelength polymerization was previously used to break the diffraction limit in 2D and semi-3D lithography. We are exploiting this phenomenon to implement a highly parallelized fully-three-dimensional method. Since the multi-wavelength polymerization requires relatively low illumination intensities, a low cost full-field illumination system can be implemented increasing the printing speed by several orders of magnitude. The existing nano- and micro-3D printing methods demonstrated an outstanding potential in rapid prototyping of a wide range of applications ranging from micro-optics to micro-fluidics and bio-scaffolds. We believe that our approach will shift the paradigm of micro-3D printing from prototyping and R&D applications to serial production of final products.