Fundamental understanding of physiological processes that occur at biological membranes, such as membrane fusion, necessitates addressing not only the biochemical aspects, but also biophysical aspects such as membrane tension and curvature. In this talk, I will show how we combine membrane model systems, micropipette aspiration, optical tweezers, and confocal fluorescence microscopy to study membrane shaping and remodelling. I will describe a tool we developed in which membrane bilayers are formed on polystyrene microspheres that can be trapped and manipulated with optical tweezers and brought into contact with micropipette-aspirated vesicles. Using this system, we demonstrated that membrane tension inhibits hemifusion by increasing the energy barrier for stalk formation. (Shendrik et al 2023). We then extended the approach to interact supported membranes with asymmetric GUVs, revealing a preferred direction for fusion in asymmetric membranes (Shendrik et al 2025). Expanding our understanding of how membrane tension affects membrane organization, we also explored the effect of membrane stretching on phase-separated membranes (Perlman-Illouz et al 2026). Finally, I will show how biomimetic models can be used to gain mechanistic insight into the action mechanisms of viral fusion proteins (Yosibash I. et al 2025). Together, these studies demonstrate how combining mechanical tools with biomimetic models advances our mechanistic understanding of cell membranes. FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.bio
