Three-dimensional photochemical microfabrication of poly(3,4-ethylene- dioxythiophene) in transparent polymer sheet

• Multi-photon sensitized polymerization of 3,4-ethylenedioxythiophene (EDOT).
• Three-dimensional microstructures of poly(EDOT) in the transparent polymer sheet.
• The dimeric compound of EDOT was employed as the starting material.
• The lateral precision of this system exceeded the diffraction limit.

A dimeric compound of 3,4-ethylenedioxythiophene was polymerized to form poly(3,4-ethylenedioxythiophene) by multi-photon sensitized polymerization using a femtosecond laser. In contrast, photopolymerization could not be achieved using 3,4-ethylenedioxythiophene as the starting material, because it has a more positive oxidation peak potential compared to the redox potential of the tris(2,2′-bipyridyl)ruthenium complex used as the photosensitizer. Furthermore, three-dimensional micropatterns of poly(3,4-ethylenedioxythiophene) could be produced in a transparent polymer sheet by scanning the laser focal point.