Two-photon "depolymerization" enables a flexible patterning of positive-tone photoresists on a broad range of opaque and transparent substrates. High-resolution 2D patterns with finest features can directly be structured into the photoresist without the need of expensive masks.
This bridges the gap between electron beam lithography and direct laser writing systems based on 1-photon absorption. The photoresist patterns can then be transfered to the substrate by means of etching of material deposition and subsequent lift-off process.
By using galvanization processes it is also possible to use the 2D structures as molds to shape metal parts.