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Nano-3D-printed Photochromic Objects

submitted on 31.08.2020, 13:29 and posted on 01.09.2020, 12:24 by Sebastian Ulrich, Xiaopu Wang, Markus Rottmar, René M. Rossi, Bradley J. Nelson, Nico Bruns, Ralph Müller, Katharina Maniura-Weber, Xiao-Hua Qin, Luciano F. Boesel
A new class of photoresist is described for direct laser writing of photoswitchable 3D microstructures. The material comprising off-stoichiometric thiol-ene photo-clickable resins enables rapid two-photon laser processing of highly complex structures and facile post-modification with photoswitches. The microstructures were functionalized with a series of donor-acceptor Stenhouse adducts (DASAs) photoswitches with different excitation wavelength. The versatility of thiol–ene photo-click reaction enabled fine-tuning of the network structure and physical properties as well as the type and concentration of DASA photoswitches. When exposed to visible light, these microstructures exhibit excellent photo-responsiveness and undergo reversible color-changing via photoisomerization of DASA moieties. We describe that the weak fluorescence of DASAs can be used as a reporter of photoswitching, color changes, and thermal recovery, allowing the reading of DASA-containing sub-micrometric structures in 3D. This work delivers a new approach for custom microfabrication of 3D photochromic objects with molecularly engineered color and responsiveness.


Swiss National Science Foundation Project Fund

ETH Zurich Career Seed Grant

Swiss National Science Foundation, Spark Grrant


Email Address of Submitting Author


ETH Zurich



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interests

Version Notes

V1.0, 2020-08-31