The goal of this project is to use chemical sensors and biophysical tools to address the cell as a physical object, which is subject to forces, pressures and tensions. These physical constraints have a major impact on the shape and function of cells and tissues, ultimately feeding back and determining the biochemistry of living matter. The project is dedicated to the detection of mechanical forces in model membranes, membranes of single cells as well as cells in tissues including those dividing asymmetrically or in an oriented fashion. Membrane probes called “fluorescent flippers” or planarizable push–pull probes were developed in the past years which arrive as a magic bullet to start achieving robust, direct measurements of tension properties in membranes, cells and tissues. Rationally designed, they can be imaged by fluorescence life time microscopy (FLIM) and used to perform pioneering experiments in vivo and in culture cells, e.g. to access the inner leaflet of cells and reach the diversity of intracellular membrane compartments beyond the plasma membrane, and solve key questions in mechanobiology. Flippers coupled to quantum dots functionalized by CPDs can also be used to carry targeting signals to different compartments. Secondly, our project aims to integrate measurements with theory based on theoretical physics to develop quantitative models in cell and developmental biology.