The Macromolecular Engineering Laboratory (Prof. Mark W. Tibbitt) within the Department of Mechanical and Process Engineering (D-MAVT) at ETH Zurich in Zurich, Switzerland engineers and applies advanced polymeric materials for a range of biomedical and industrial uses. The recent focus of the group (www.macro.ethz.ch/) includes the development of: (i) rational design of dynamic polymer networks; (ii) (bio)material processing; (iii) organ perfusion and regeneration; (iv) tools to study mechanobiology and cell–matrix interactions; and (v) engineered drug delivery systems. The lab is composed of a highly interdisciplinary and international team of motivated researchers. To expand on our understanding of how molecular-scale features govern the mechanics and flow of dynamic covalent hydrogels, we are recruiting a full-time (100%) doctoral candidate, with an intended starting date on or after 01. October 2026.

Dynamic covalent hydrogels (DCHs)—polymer networks cross-linked by reversible covalent bonds, such as boronate esters, hydrazones, imines, or disulfides—represent a compelling class of viscoelastic soft materials. Their tailorable mechanical properties, stimulus-responsiveness, and processability (injectable, printable) make them highly attractive for biomedical and industrial uses. However, the rational engineering of DCHs remains constrained by an incomplete understanding of how molecular-level features—bond thermodynamics, kinetics, network architecture—translate into macroscopic material properties such as the plateau modulus (G0) and the relaxation time (tR). Building a rigorous, quantitative framework linking molecular behavior to macroscale properties is the central aim of this project.

This doctoral project has two main, interrelated thrusts. In the first, the student will synthesize and characterize a broad library of model DCHs spanning a range of dynamic covalent chemistries (boronate ester, hydrazone, imine, and disulfide bonds) and network architectures (ideal, real, and interpenetrating networks). The student will quantify the equilibrium binding constants, binding thermodynamics, and reaction kinetics of the reversible cross-links using isothermal titration calorimetry (ITC), NMR spectroscopy (including 2D EXSY), and UV-vis/fluorescence techniques, and relate these to the macroscale rheological properties measured by shear rheometry and nano-indentation. A key and largely unexplored question is how the macromolecular nature of the binding partners — as opposed to small-molecule analogues — influences binding behavior and network mechanics, which the student will investigate systematically. In the second thrust, the student will develop theoretical and computational frameworks, in close collaboration with Prof. Vlasios Mavrantzas (a collaborator in the lab), to capture entropy-driven network-scale effects and refine rubber elasticity models for dynamic networks. Complementary studies of non-linear flow behavior using shear rheometry and microfluidic flow cells will provide insight into DCH processability for injectable biomaterial design.

The doctoral student will work in close collaboration with and be supported by an interdisciplinary team of doctoral students and postdocs working on related topics. In addition to research, the PhD candidate is expected to contribute to lab duties and will have the opportunity to contribute to teaching within the group, including student supervision, lecture support, and practical courses in the lab.

We are seeking a curious, motivated, and self-driven individual, who is comfortable working on interdisciplinary projects spanning macromolecular chemistry, soft matter physics, and physical chemistry. Academic excellence, a professional work attitude, and a proactive and self-driven work ethic are expected. Moreover, the candidate must be able to fluently communicate in English (oral and written) and be willing to work in a highly interactive, international team. Applicants must hold a MSc degree in chemical engineering, mechanical engineering, chemistry, materials science, physics, polymer science, or related fields. A working knowledge of organic synthesis and polymer chemistry is required. Practical experience in one or more of the following would be advantageous: rheological characterization of soft materials, calorimetric or spectroscopic analysis of molecular binding (ITC, NMR, UV-vis), design of polymer networks, or computational modeling of polymeric systems. The doctoral position is intended for 4 years, at 100% employment, and will be supervised by Prof. Dr. Mark Tibbitt. The position is funded by the Swiss National Science Foundation and is conditional upon admission to the Doctoral Program at ETH Zurich.

The position is hosted in the Department of Mechanical and Process Engineering (D-MAVT) of the ETH Zurich, in the Zentrum Campus in Zurich, Switzerland. D-MAVT (https://mavt.ethz.ch/) is an interdisciplinary department with focus areas in process/chemical, mechanical, and biomedical engineering as well as robotics and controls. ETH Zurich (https://ethz.ch/en/) is a global leader in science and engineering and consistently ranks among the top universities in the world. Zurich is an international city with broad access to outdoor activities, arts and culture, other European cities, as well as a rich and excellent scientific community.

We look forward to receiving your application, as a single PDF, including: 1) a cover letter of motivation that describes your scientific interest in this position and main scientific achievements to date (max. 2 pages), 2) CV, 3) diplomas and course transcripts, and 4) the contact details of three or more references. Please submit your application on-line. Applications via email or post will not be considered. For questions about the position, please contact Prof. Tibbitt (mtibbitt AT ethz DOT ch) (note that applications cannot be accepted by email).