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Dorothea Helmer

Group Leader

Department of Microsystems Engineering (IMTEK)
Albert-Ludwigs University of Freiburg
Georges-Köhler-Allee 103 | 79110 Freiburg im Breisgau | Germany

 

dorothea.helmer@imtek.de

Curriculum Vitae

Professional experience

  • since 10/2020: Group leader at FMF of the BMBF NanoMat Futur Research Group „MatrixPrint“
  • since 10/2014: Postdoc at the NeptunLab
  • 2009 – 2014: PhD thesis (Dr. rer. nat. final grade: 1.0, organic chemistry and biochemistry),Synthesis and Test of Peptides and Peptoids for the Inhibition of Cytokines, Prof. Katja Schmitz (Technical University of Darmstadt TUD)
  • 2004 – 2009: Studies in chemistry (University of Karlsruhe), final grade: 1.2

Awards

Journal Papers

D. Böcherer, Y. Li, S. Kluck, N. Nekoonam, P.D. Böcherer, Y. Li, S. Kluck, N. Nekoonam, P.Zhu, B.E. Rapp, F. Kotz-Helmer, D. Helmer, COLOR3D – Multicolored 3D printing of wood composites by submicron structuring, Additive Manufacturing, 10.1016/j.addma.2023.103723. | Link

N. Nekoonam, G. Vera, A. Goralczyk, F. Mayoussi, P. Zhu, D. Böcherer, A. Shakeel, D. Helmer, Controllable Wetting Transitions on Photoswitchable Physical Gels, ACS Appl. Mater. Interfaces, 2023, 15, 22, 27234–27242. | Link

F. Mayoussi, A. Usama, N. Nekoonam, I. Knauer, D. Böcherer, B. E. Rapp, D. Helmer, Influence of Parylene F Coatings on the Wetting Properties of Soft Polydimethylsiloxane (PDMS), Materials, 2023, 16(5), 1938 | Link | Link

A. Goralczyk, S. Bhagwat, F. Mayoussi, N. Nekoonam, K. Sachsenheimer, P. Hou, F. Kotz-Helmer, D. Helmer, B. E. Rapp, Application of Micro/Nanoporous Fluoropolymers with Reduced Bioadhesion in Digital Microfluidics, Nanomaterials, 2022, 12(13), 2201 | Link

P. Pezeshkpour, K. Sachsenheimer, A. Goralczyk, F. Mayoussi, M. Mader, F. Kotz-Helmer, D. Helmer, B. E. Rapp, A Real-Time Capacitive Sensor to Detect the Stability of Salvinia Layers on Porous Superhydrophobic Polymers Under Shear, Adv. Mater. Technol., 2022, 2200287 | Link

S. Bhagwat, C.O'Brien, A. Hamza, S. Sharma, C. Rein, M. Sanjaya, D. Helmer, F. Kotz-Helmer, P. Pezeshkpour, B.E.Rapp, An On-Chip Liquid Metal Plug Generator, Adv. Mater. 2022, 2201469 | Link

A. Goralczyk, M. Zhu, F. Mayoussi, M. Lallemang, M. Tschaikowsky, A. Warmbold, S. Caliaro, F. Tauber, B. N. Balzer, F. Kotz-Helmer, D. Helmer, B. E. Rapp, Study of repellence on polymeric surfaces with two individually adjustable pore hierarchies, Chem. Eng. J. 2022, 437, 135287 | Link

S. Franco Corredor, F. Mayoussi, M. Luitz, A. Kick, A. Goralczyk, D. Böcherer, G. Vera, D. Helmer, F. Kotz-Helmer, B. E. Rapp, A Polystyrene Photoresin for Direct Lithography of Microfluidic Chips. Adv. Mater. Technol. 2022, 2200084 | Link

M. Mader, L. Hambitzer, P. Schlautmann, S. Jenne, C. Greiner, F. Hirth, D. Helmer, F. Kotz-Helmer, B.E. Rapp: "Melt-Extrusion-Based Additive Manufacturing of Transparent Fused Silica Glass", Adv. Sci., 2021, 8, 2103180 | Link

F. Mayoussi, E. H. Doeven, A. Kick, A. Goralczyk, Y. Thomann, P. Risch, R. M. Guijt, F. Kotz, D. Helmer, B. E. Rapp: "Facile fabrication of micro-/nanostructured, superhydrophobic membranes with adjustable porosity by 3D printing", Journal of Materials Chemistry A, 2021 | Link

Engemeann, I. Rink, M. F. Kilb, M. Hungsberg, D. Helmer, K. Schmitz: "Cell-based actin polymerization assay to analyze chemokine inhibitors", Journal of Pharmacological and Toxicological Methods, 2021 | Link

Kotz, A. S. Quick, P. Risch, T. Martin, T. Hoose, M. Thiel, D. Helmer, B. E. Rapp: “Two‐Photon Polymerization of Nanocomposites for the Fabrication of Transparent Fused Silica Glass Microstructures”, Advanced Materials, 33, 9, 2006341, 2021 | Link

Mader, O. Schlatter, B. Heck, A. Warmbold, A. Dorn, H. Zappe, P. Risch, D. Helmer, F. Kotz, B. E. Rapp: “High-throughput injection molding of transparent fused silica glass”, Science, 2021 | Link

Helmer, B. E. Rapp: "Divide and Print", Nature Materials, 19, 131-133, 2020 | Link

Kotz, M. Mader, N. Dellen, P. Risch, A. Kick, D. Helmer, B. E. Rapp: “Fused deposition modeling of microfluidic chips in polymethylmethacrylate”, Micromachines, 11(9), 873, 2020. | Link

Keller, J. Bruchmann, T. Sollich, C. Richter, R. Thelen, F. Kotz, T. Schwartz, D. Helmer, B. E. Rapp: "Study of Biofilm Growth on Slippery Liquid-Infused Porous Surfaces Made from Fluoropor", ACS Applied Materials & Interfaces, 11, 4480-4487, 2019 | Link

F. Kotz, P. Risch, K. Arnold, S. Sevim, J. Puigmarti-Luis, A. Quick, M. Thiel, A. Hrynevich, P. Dalton, D. Helmer, B. E. Rapp: “Fabrication of arbitrary three-dimensional suspended hollow microstructures in transparent fused silica glass”, Nature Communication, 10, 1439, 2019 | Link

Risch, D. Helmer, F. Kotz, B. E. Rapp: "Analytical solution of the time-dependent microfluidic poiseuille flow in rectangular channel cross-sections and its numerical implementation in Microsoft Excel", Biosensors, 9(2), 67, 2019 | Link

Sachsenheimer, C. Richter, D. Helmer, F. Kotz, B. E. Rapp: "A Nontoxic Battery with 3D-printed housing for on-demand operation of microcontrollers in microfluidic sensors", Micromachines, 10, 599, 2019 | Link

F. Kotz, N. Schneider, A. Striegel, A. Wolfschläger, N. Keller, M. Worgull, W. Bauer, D. Schild, M. Milich, C. Greiner, D. Helmer, B. E. Rapp: “Glassomer: Processing Fused Silica Glass like a Polymer”, Advanced Materials, 30, 1707100, 2018 | Link | Cover

T. M. Nargang, R. Dierkes, J. Bruchmann, N. Keller, K. Sachsenheimer, C. Lee-Thedieck, F. Kotz, D. Helmer and B. E. Rapp: "Photolithographic structuring of soft, extremely foldable and autoclavable hydrophobic barriers in paper", Analytical Methods, 10, 4028-4035, 2018 | Link

Kotz, P. Risch, D. Helmer, B. E. Rapp: “Highly Fluorinated Methacrylates for Optical 3D Printing of Microfluidic Devices”, Micromachines, 9, 3, 15, 2018 (invited) | Link

Helmer, N. Keller, F. Kotz, F. Stolz, C. Greiner, T. M. Nargang, K. Sachsenheimer, B. E. Rapp: „Transparent, abrasion-insensitive superhydrophobic coatings for real-world applications”, Nature Scientific Reports, 7, 1, 15078, 2017. | Link

Richter, F. Kotz, N. Keller, T. M. Nargang, K. Sachsenheimer, D. Helmer, B. E. Rapp: “An Analytical Solution to Neumann-Type Mixed Boundary Poiseuille Microfluidic Flow in Rectangular Channel Cross-Sections (Slip/No-Slip) Including a Numerical Technique to Derive It”, Journal of Biomedical Science and Engineering, 10, 205-219, 2017 | Link

Helmer, A. Voigt, S. Wagner, N. Keller, K. Sachsenheimer, F. Kotz, T. M. Nargang, B. E. Rapp: "Suspended Liquid Subtractive Lithography: One-step generation of 3D channel geometries in viscous curable polymer matrices", Nature Scientific Reports 7, 7387, 2017 | Link

F. Kotz, K. Arnold, S. Wagner, W. Bauer, N. Keller, T. M. Nargang, D. Helmer, B. E. Rapp: "Liquid PMMA: A High Resolution Polymethylmethacrylate Negative Photoresist as Enabling Material for Direct Printing of Microfluidic Chips", Advanced Engineering Materials, 20, 1700699, 2017 | Link | Cover

Kotz, K. Arnold, W. Bauer, D. Schild, N. Keller, K. Sachsenheimer, T. M. Nargang, C. Richter, D. Helmer, B. E. Rapp: "Three-dimensional Printing of Transparent Fused Silica Glass", Nature, 544, 337-339, 2017 | Link | Media Coverage | Video

Richter, K. Sachsenheimer, N. Keller, T. M. Nargang, D. Helmer, F. Kotz, B. E. Rapp: "An individual addressable and latchable actuator array for microfluidic systems", Microfluid Nanofluid 20:130, 2016. | Link

Richter, F. Kotz, S. Giselbrecht, D. Helmer, B. E. Rapp: "Numerics made easy: solving the Navier–Stokes equation for arbitrary channel cross-sections using Microsoft Excel", Biomedical Microdevices 18:52, 2016 | Link

Helmer, K. Brahm, C. Helmer, J. S. Wack, G. Brenner-Weiss, K. Schmitz: "Two-channel image analysis method for the screening of OBOC libraries", Analytical Methods, 2016 | Link

Kotz, K. Plewa, W. Bauer, N. Schneider, N. Keller, T. Nargang, D. Helmer, K. Sachsenheimer, M. Schäfer, M. Worgull, C. Greiner, C. Richter, B. E. Rapp: “Liquid Glass: A Facile Soft Replication Method for Structuring Glass”, Advanced Materials, 28, 4646-4650, 2016 | Link | Media Coverage

Keller, T. M. Nargang, M. Runck, F. Kotz, A. Striegel, K. Sachsenheimer, D. Klemm, K. Länge, M. Worgull, C. Richter, D. Helmer, B. E. Rapp: "Tacky Cyclo Olefin Copolymer: A biocompatible bonding technique for the fabrication of microfluidic channels in COC", Lab Chip, 16, 1561-1564, 2016 | Link

M. Nargang, M. Runck, D. Helmer, B. E. Rapp: "Functionalization of paper using photobleaching: a fast and convenient method for creating paper-based assays with colorimetric and fluorescent readout", Engineering in Life Sciences, 2016 | Link

Helmer, I. Rink, J. A. R. Dalton, K. Brahm, M. Jöst, T. M. Nargang, W. Blum, P. Wadhwani, G. Brenner-Weiss, B. E. Rapp, J. Giraldo, K. Schmitz: “Rational design of a peptide capture agent for CXCL8 based on a model of the CXCL8:CXCR1 complex”, RSC Advances, 5, 25657-25668, 2015 | Link

Rink, J. Rink, D. Helmer, D. Sachs, K. Schmitz: "A Haptotaxis Assay for Leukocytes Based on Surface-Bound Chemokine Gradients", Journal of Immunology, 2015 | Link

M. Nargang, L. Brockmann, P. Nikolov, D. Schild, D. Helmer, N. Keller, K. Sachsenheimer, E. Wilhelm, L. Pires, M. Dirschka, A. Kolew, M. Worgull, S. Giselbrecht, C. Neumann, B. E. Rapp: “Liquid polystyrene: a room-temperature photocurable soft lithography compatible pour-and-cure-type polystyrene”, Lab Chip (special issue “Emerging Investigators"), 14, 2698-2708, 2014 | Link

Reviews

Kotz, P. Risch, D. Helmer, B. E. Rapp: “High-performance materials for 3D printing in chemical synthesis applications”, Advanced Materials (invited), 2019 | Link

Books and Book chapters

Kotz, D. Helmer, B. E. Rapp: “Emerging Technologies and Materials for High-Resolution 3D Printing of Microfluidic Chips”, book chapter within "Advances in Biochemical Engineering/Biotechnology", Springer Nature, 2020 | Link

Kotz, D. Helmer, B. E. Rapp: “3D Printing of Transparent Glasses”, book chapter within "3D Printing of Optical Components", 169-184, Springer, 2020 | Link

Helmer, K. Schmitz: „Peptides and Peptide Analogs to Inhibit Protein-Protein Interactions“, Böldicke (ed.) Protein Targeting – Prediction, Selection and Activity of Specific Inhibitors, Springer, 2015 | Link

Helmer: “Synthesis and Test of Peptides and Peptoids for the Inhibition of Cytokines”, Cuvillier Verlag, Göttingen, 2015 | Link

Conference Contributions

A Kick, D Helmer, F Kotz, B Rapp:“Generation of multi-level microstructures using a wavelength-selective photoresist and mask-less grayscale lithography”, talk, SPIE Photonics West, San Francisco, USA, 2020

Kotz, P. Risch, M. Thiel, A. Quick, D. Helmer, B. E. Rapp: “Sacrificial Template Replication: Fabrication of arbitrary 3D microfluidic channels in transparent fused silica glass”, talk, SPIE Photonics West, San Francisco, USA, 2020

Helmer, F. Kotz, B. E. Rapp: „Suspended liquid subtractive lithography: printing three dimensional channels directly into uncured polymeric matrices”, talk, SPIE Photonics West, San Francisco, 2019

Risch, F. Kotz, D. Helmer, B. E. Rapp: „3D printing of highly fluorinated methacrylates for the rapid prototyping of transparent and chemically-resistant microfluidic devices”, talk, SPIE Photonics West, San Francisco, 2019

M. Nargang, R. Dierkes, J. Bruchmann, N. Keller, K. Sachsenheimer, F. Kotz, D. Helmer, B. E. Rapp: „Structuring unbreakable and autoclavable hydrophobic barriers in paper via direct printing and mask-based photolithography”, talk, SPIE Photonics West, San Francisco, 2019

Kotz, P. Risch, K. Arnold, D. Helmer, B. E. Rapp: “Next generation 3D printing - The emergence of enabling materials”, talk, SPIE Defence and Security, Berlin, Germany, 2018 | Link

Kotz, A. Striegel, N. Schneider, P. Risch, M. Worgull, D. Helmer, B. E. Rapp: "High-throughput polymer molding of transparent fused silica microfluidic chips", poster, 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Kaohsiung, Taiwan, 2018

Risch, F. Kotz, D. Helmer, B. E. Rapp: "3D printing of microfluidic glass reactors", poster, 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Kaohsiung, Taiwan, 2018

Risch, F. Kotz, D. Helmer, B. E. Rapp: "3D printing of highly fluorinated methacrylates for the fabrication of transparent and chemically resistant microfluidic devices", poster, 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Kaohsiung, Taiwan, 2018

Kotz, A. Striegel, N. Schneider, M. Worgull, D. Helmer, B. E. Rapp: „High-throughput structuring of fused silica glass“; talk, MNE, Kopenhagen, 2018

Helmer: "Suspended Liquid Subtractive Lithography - Fabrication of three-dimensional microchannels by the immersion of "liquid threads"", talk, Microfluidics in the Upper Rhine Valley, IS2M Mulhouse 2018

Kotz, D. Helmer, B. E. Rapp: "Additive manufacturing of microfluidic glass chips", talk, SPIE Photonics West, San Francisco, USA, 2018 | Link

Helmer, A. Voigt, S. Wagner, N. Keller, K. Sachsenheimer, F. Kotz, T. M. Nargang, B. E. Rapp: "Additive manufacturing of microfluidic glass chips", talk, SPIE Photonics West, San Francisco, USA, 2018

Helmer, A. Voigt, B. E. Rapp: "Suspended Liquid Subtractive Lithography (SLSL) – 3D printing of microfluidic structures directly into PDMS", 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Savannah, USA, 2017

Kotz, D. Helmer, B. E. Rapp: "3D printing of microfluidic devices in highly fluorinated perfluoropolyethers (PFPE)", poster, 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Savannah, USA, 2017

M. Nargang, F. Kotz, N. Keller, D. Helmer, B. E. Rapp: “Rapid structuring of proteins on filter paper using lithography”, talk, SPIE Photonics West, San Francisco, USA, 2017 | Link

Helmer, A. Voigt, S. Wagner, B. E. Rapp: "Rapid printing in PDMS – fused deposition modeling (FDM) meets microfluidics", talk, 20th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Dublin, Ireland, 2016

M. Nargang, E. Wilhelm, F. Kotz, D. Helmer, B. E. Rapp: “UV-light based structuring of unbreakable hydrophobic barriers on commonly used papers”, poster, 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Gyeongju, Korea, 2015

Helmer, N. Keller, B. E. Rapp: “Photolithographic structuring of highly fluorinated polymers for the fabrication of microfluidic chips”, talk, 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), Gyeongju, Korea, 2015

Helmer, N. Keller, B. E. Rapp: “Reversibly Photoswitchable Hydrophilic/Hydrophobic Surfaces”, talk, ECOSS, Barcelona, Spain, 2015

Kotz, N. Keller, T.M. Nargang, K. Sachsenheimer, M. Dirschka, D. Helmer, C. Neumann, Bastian E. Rapp: “Computer aided microfluidics (CAMF): from 3D model to physical structures in less than a day”, talk, Euroanalysis, Bordeaux, France, 2015

M. Nargang, L. Brockmann, P. Nikolov, D. Schild, D. Helmer, N. Keller, M. Dirschka, A. Kolew, M. Worgull, S. Giselbrecht, C. Neumann, B. E. Rapp: “‘Liquid polystyrene’: a photocurable liquid polystyrene prepolymer as new material for microfluidic prototyping”, poster, 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS), San Antonio, USA, 2014

Patents

E. Rapp, D. Helmer, C. Richter, N. Keller: “Highly fluorinated nanostructured polymer foams for producing super-repellent surface”, WO2018065094A1, 2016 | Link

E. Rapp, D. Helmer, C. Richter, N. Keller: "Hochfluorierte nanostrukturierte Polymerschäume zur Herstellung superabweisender Oberflächen", DE102016012001A1, 2016 | Link

E. Rapp, D. Helmer, A. Voigt: "Method and apparatus for generating a three-dimensional structure in a matrix“, EP3305495A1, 2016 | Link

E. Rapp, D. Helmer, A. Voigt: "Verfahren und Vorrichtung zur Erzeugung einer dreidimensionalen Struktur in einer Matrix", DE102016219192, 2016 | Link

Miscellaneous

Helmer, B. E. Rapp: "Superabweisende Oberflächen - Die Entwicklung eines superhydrophoben Werkstoffs", GIT Labor-Fachzeitschrift, 2018 | Link

Helmer, B. E. Rapp: "Healthcare Material Platforms", HEALTH 2, Paneuropean Network, 2017. The NeptunLab is features on the cover page of the issue | Link | Cover

Interesse geweckt?

Weit hinten, hinter den Wortbergen, fern der Länder Vokalien und Konsonantien leben die Blindtexte. Abgeschieden wohnen sie in Buchstabhausen an der Küste des Semantik, eines großen Sprachozeans.

All Publications