Synergistic, Orthogonal, and Antagonistic Photochemistry for Light‐Induced 3D Printing

Abstract

3D printing techniques are often based on light‐induced chemical reactions, driven by the fascinating and powerful possibilities to control light in space and time. To date, these approaches are usually restricted to a single color of light, which does not do justice to light as an entire spectrum of distinct wavelengths. It is possible to further tap into the vast potential of light‐induced 3D printing by introducing a second color of light. While the complexity of photochemical interactions in two‐color systems is greatly increased, it concomitantly allows for enhanced control over manufacturing speed and resolution. In general, three types of two‐color interactions can be distinguished, i.e., synergistic, orthogonal, and antagonistic. In recent years, intriguing printing techniques with superior potential for the fabrication of 3D structures are emerging that require two colors of light. Their future development potential is vast yet needs to be critically underpinned by an advance in complex tunable photochemical reaction systems. The current perspective will thus explore the potential for using synergistic, orthogonal, and antagonistic photochemistries in 3D printing.

Fluorescence-readout as a powerful macromolecular characterisation tool

“…Two-colour printing is generally based on synergistic, orthogonal or antagonistic photochemistry. 469 Synergistic photochemistry requires the simultaneous irradiation with two distinct colours to trigger a reaction, in an orthogonal system two reactions are induced by two wavelengths and proceed independently, while antagonistic implies opposing reaction processes triggered separately by two colours of light. Two-colour systems not only allow access to new and complex materials with unique properties, but also facilitate the development of superior printing approaches and techniques, such as light-sheet printing, 470 xolography, 471 multimaterial printing 53,472 and STED-based nanoprinting.…”

Upgrading the Toolbox: Two‐Photon Absorption Induced Cleavage of Coumarin Dimers for Light‐Based 4D Printing

“…The wavelength orthogonality of the photochemical reactions is essential for this process, with different chemical reactions triggered by different illumination wavelengths. [14,15] Moreover, the presented photochemical tool allows for in-depth modifications.…”

Wavelength-resolved near infra-red light induced free-radical polymerization

“…Over the last decade, photochemistry has seen a remarkable renaissance, moving from broadly emitting light sources to trigger reactions 1-7 into the realm of precision chemistry triggered by orthogonal, antagonistic or synergistically operating wavelengths. [8][9][10][11][12][13][14][15][16][17] In particular, applications such as tissue engineering, [18][19][20][21] 3D additive manufacturing fabrication [22][23][24][25][26][27] and highly customized photopolymerization [28][29][30] have witnessed substantial progress. Photopolymerizationsincluding the herein considered radical variantfeature key advantages due to their inherent spatiotemporal control and mild reaction conditions.…”