Two-Photon Polymerization (2PP) has attracted broad interest for the fabrication of microoptical elements due to its design flexibility and precision. Along with tailored hybrid polymers a higher level of functional integration and new application concepts are enabled. As the entire volume of the desired 3D structure is filled in a point-by-point fashion, the fabrication can require several days inhibiting the adoption of 2PP as an additive manufacturing process at industrial level. We review different strategies to overcome the limitation in throughput and their impact on the patterning result. Particularly, processing using galvoscanner technology and replication of 2PP structures are highlighted.
We demonstrate the printing of a complex smart integrated system using only five functional inks: the fluoropolymer
P(VDF:TrFE) (Poly(vinylidene fluoride trifluoroethylene) sensor ink, the conductive polymer PEDOT:PSS (poly(3,4
ethylenedioxythiophene):poly(styrene sulfonic acid) ink, a conductive carbon paste, a polymeric electrolyte and SU8 for
separation. The result is a touchless human-machine interface, including piezo- and pyroelectric sensor pixels (sensitive
to pressure changes and impinging infrared light), transistors for impedance matching and signal conditioning, and an
electrochromic display. Applications may not only emerge in human-machine interfaces, but also in transient
temperature or pressure sensing used in safety technology, in artificial skins and in disposable sensor labels.