Markus M. Zieger
Karlsruhe Institute of Technology
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Featured researches published by Markus M. Zieger.
Angewandte Chemie | 2017
Markus M. Zieger; Patrick Mueller; Alexander S. Quick; Martin Wegener; Christopher Barner-Kowollik
Using an advanced functional photoresist we introduce direct-laser-written (DLW) 3D microstructures capable of complete degradation on demand. The networks consist exclusively of reversible bonds, formed by irradiation of a phenacyl sulfide linker, giving disulfide bonds in a radical-free step-growth polymerization via a reactive thioaldehyde. The bond formation was verified in solution by ESI-MS. To induce cleavage, dithiothreitol causes a thiol-disulfide exchange, erasing the written structure. The mild cleavage of the disulfide network is highly orthogonal to other, for example, acrylate-based DLW structures. To emphasize this aspect, DLW structures were prepared incorporating reversible structural elements into a non-reversible acrylate-based standard scaffold, confirming subsequent selective cleavage. The high lateral resolution achievable was verified by the preparation of well-defined line gratings with line separations of down to 300 nm.
ACS Nano | 2017
Patrick Mueller; Markus M. Zieger; Benjamin Richter; Alexander S. Quick; Joachim Fischer; Jonathan B. Mueller; Lu Zhou; Gerd Ulrich Nienhaus; Martin Bastmeyer; Christopher Barner-Kowollik; Martin Wegener
Recent developments in stimulated-emission depletion (STED) microscopy have led to a step change in the achievable resolution and allowed breaking the diffraction limit by large factors. The core principle is based on a reversible molecular switch, allowing for light-triggered activation and deactivation in combination with a laser focus that incorporates a point or line of zero intensity. In the past years, the concept has been transferred from microscopy to maskless laser lithography, namely direct laser writing (DLW), in order to overcome the diffraction limit for optical lithography. Herein, we propose and experimentally introduce a system that realizes such a molecular switch for lithography. Specifically, the population of intermediate-state photoenol isomers of α-methyl benzaldehydes generated by two-photon absorption at 700 nm fundamental wavelength can be reversibly depleted by simultaneous irradiation at 440 nm, suppressing the subsequent Diels-Alder cycloaddition reaction which constitutes the chemical core of the writing process. We demonstrate the potential of the proposed mechanism for STED-inspired DLW by covalently functionalizing the surface of glass substrates via the photoenol-driven STED-inspired process exploiting reversible photoenol activation with a polymerization initiator. Subsequently, macromolecules are grown from the functionalized areas and the spatially coded glass slides are characterized by atomic-force microscopy. Our approach allows lines with a full-width-at-half-maximum of down to 60 nm and line gratings with a lateral resolution of 100 nm to be written, both surpassing the diffraction limit.
Nature Communications | 2018
David Gräfe; Andreas Wickberg; Markus M. Zieger; Martin Wegener; Eva Blasco; Christopher Barner-Kowollik
Existing photoresists for 3D laser lithography that can be removed after development in a subtractive manner typically suffer from harsh cleavage conditions. Here, we report chemoselectively cleavable photoresists for 3D laser lithography based on silane crosslinkers, allowing the targeted degradation of 3D printed microstructures under mild conditions. Three bifunctional silane crosslinkers carrying various substitutions on the silicon atom are synthesized. The photoresists are prepared by mixing these silane crosslinkers with pentaerythritol triacrylate and a two-photon photoinitiator. The presence of pentaerythritol triacrylate significantly enhances the direct laser written structures with regard to resolution, while the microstructures remain cleavable. For the targeted cleavage of the fabricated 3D microstructures, simply a methanol solution including inorganic salts is required, highlighting the mild cleavage conditions. Critically, the photoresists can be cleaved selectively, which enables the sequential degradation of direct laser written structures and allows for subtractive manufacturing at the micro- and nanoscale.Subtractive manufacturing of microstructures is important for many applications, yet photoresists for 3D laser lithography allow only removal after development under harsh cleavage conditions. Here, the authors introduce a set of chemoselective cleavable photoresists allowing the orthogonal cleavage of microstructures under mild conditions.
ACS Macro Letters | 2014
Corinna M. Preuss; Markus M. Zieger; Cesar Rodriguez-Emmenegger; Nicolas Zydziak; Vanessa Trouillet; Anja S. Goldmann; Christopher Barner-Kowollik
Advanced Functional Materials | 2017
Chen Wang; Markus M. Zieger; Alexander Schenzel; Martin Wegener; Johannes Willenbacher; Christopher Barner-Kowollik; Christopher N. Bowman
Macromolecules | 2017
Jan Steinkoenig; Markus M. Zieger; Hatice Mutlu; Christopher Barner-Kowollik
Angewandte Chemie | 2017
Markus M. Zieger; Patrick Mueller; Alexander S. Quick; Martin Wegener; Christopher Barner-Kowollik
Langmuir | 2017
Markus M. Zieger; Ognen Pop-Georgievski; Andres de los Santos Pereira; Elisseos Verveniotis; Corinna M. Preuss; Matthias Zorn; Bernd Reck; Anja S. Goldmann; Cesar Rodriguez-Emmenegger; Christopher Barner-Kowollik
Advanced Functional Materials | 2018
Markus M. Zieger; Patrick Müller; Eva Blasco; Charlotte Petit; Vincent Hahn; Lukas Michalek; Hatice Mutlu; Martin Wegener; Christopher Barner-Kowollik
School of Chemistry, Physics & Mechanical Engineering; Science & Engineering Faculty | 2017
Markus M. Zieger; Patrick Mueller; Alexander S. Quick; Martin Wegener; Christopher Barner-Kowollik