Multiphoton lithography (MPL) or multiphoton processing is an umbrella term for 3D printing methods relying on photochemical reactions triggered by multiphoton absorption (MPA). The most popular approach is the two-photon polymerization (2PP), also sometimes referred to as two-photon-absorbed photopolymerization, two-photon induced polymerization, two-photon lithography, two-photon laser scanning lithography, multiphoton-excited microfabrication, 3D multiphoton lithography, 3D laser lithography or even direct laser writing. Due to multiphoton absorption it allows the realization of complex 3D structures with spatial resolution down to a 100 nm level.
In our most recent effort to demonstrate the capabilities of MPL we have produced a tiny castle (230 µm x 250 µm x 360 µm) directly on a tip of a pencil. Its design was developed in cooperation with Daniela Mitterberger and Tiziano Derme (Castle on a pencil tip via nano-scale 3D-printing). The Scanning Electron Microscopy (SEM) image of produced structure appeared on the cover of the recent book “Castle on a pencil tip via nano-scale 3D-printing”.