The bioMatter Microfluidics Group at ETH Zürich, led by Dr Eleonora Secchi and hosted within the chair of Prof. Roman Stocker, is recruiting two PhD candidates for a recently funded SNSF project focused on the biophysics and rheology of bacterial biofilms. The group investigates the physicochemical mechanisms governing microbial surface colonisation, biofilm assembly, structure, and rheology, employing interdisciplinary approaches that span materials science, microbiology, microfluidics, and advanced imaging.

The project aims to systematically study nonlinear biofilm rheology, with a particular emphasis on the role of extracellular DNA (eDNA) in stress-hardening and mechanical adaptation. Biofilms, which are microbial communities encased in a polymeric matrix, play significant roles in medicine, industry, and the environment due to their resilience and ability to cause persistent infections and biofouling. The research will experimentally investigate nonlinear rheology and stress-hardening in bacterial biofilms of various morphologies using custom microfluidic and rheometry platforms.

Candidates will quantify the role of eDNA and its interactions with biofilm matrix components through mutant libraries, enzymatic/antibody assays, and controlled physicochemical conditions, as well as assess the incorporation of exogenous DNA into biofilms. Advanced fluorescence and confocal imaging will be used to resolve biofilm network structure and eDNA conformation in situ. The project also involves developing a numerical predictive model of biofilm mechanics and collaborating within an interdisciplinary team.

The position is fully funded for approximately four years, with final admission to the doctoral programme contingent on a successful Aptitude Colloquium at the end of the first year. Applicants should hold a Master’s degree in physics, biophysics, materials science, microbiology, or a related field, and have experience in experimental work such as microfluidics, rheology, microscopy, or culturing microbes.

Familiarity with data analysis and quantitative modelling is highly valued. The group offers training opportunities, career development perspectives, mentoring, and a supportive, diverse, and inclusive working environment. Applications must be submitted online by November 30th, 2025, including a CV, cover letter, transcripts, thesis PDF, and two reference letters.

For questions about the position, contact Dr Eleonora Secchi at [email protected].