Fluid mechanics at the cellular membrane

The mechanical and chemical interactions between cells and their surroundings dictate their behavior, such as motion, growth, and proliferation. Such interactions are mediated by the cell’s membrane, a thin layer composed of a lipid bilayer and embedded proteins. The membrane’s functions include the transport of molecules and ions, and sensing (or signaling); therefore, it is crucial for homeostasis, or the maintenance of a stable internal state. Controlled studies into membrane mechanics have been limited by complexities in geometry and detection of forces at the scale of pico-Newtons. To address these challenges, we use novel force measurement techniques with optical tweezers to probe the hydrodynamic flow around free-standing lipid bilayers within microfluidic channels. The aims of these measurements are to quantify the interfacial tension of lipid bilayers and fluid slip close to the layer surface, building towards a fundamental understanding of the physical principle governing the hydrodynamics around membranes.