High resolution femtosecond direct laser writing with wrapped lens
Andrea Toulouse, Simon Thiele, Kai Hirzel, M. Schmid, Ksenia Weber, Maria Zyrianova, Harald Gießen, Alois Herkommer, Michaël Heymann
Abstract
Wrapped writing mode is a simple, inexpensive approach to multiphoton stereolithography. Standard ∼10 µm thin cling foil shields the objective from direct contact with the photoresist, without compromising writing resolution. A diffraction limited lateral voxel width below 150 nm was demonstrated through ray tracing simulations and electron microscopy using standard polymer photoresist. Wrapped mode, like dip-in printing, is not limited by the objective working distance height. Its utility to prototype new print resists was validated through custom aqueous protein, silver nitrate, and black epoxy based formulations.