Electromechanics of charged-biological membranes: dynamics, instabilities, and signaling

How do biological membranes respond to electric fields? This question lies at the heart of processes ranging from neuronal excitability, signal transduction, ion transport, and electroporation. Although most biological membranes are composed of lipids with charged head groups, the role of these surface charges in shaping the dynamical behaviors of membranes-as well as their stability-under electric fields has remained unexplored due to the lack of appropriate theoretical tools. A key gap is a tractable non-equilibrium framework that couples electrolyte transport with membrane electromechanics and hydrodynamics that does not assume a zero-thickness membrane.

In this talk, using a newly developed framework known as the 2+delta theory, we will analyze how charged biological membranes of finite thickness maintain their mechanical integrity, or destabilize, under electrical stimuli. We show how coupled electromechanical behaviors can drive membrane instabilities and underlie processes such as pore formation. If time permits, I will also discuss how the opening ion channels perturbs membrane tension, illustrating the intimate coupling between transmembrane ionic currents and membrane mechanics that may underlie signal propagation in excitable cells. Our findings provide new insights into the coupled electrochemical and mechanical dynamics of biological membranes, and establish a unified and predictive framework for understanding, and potentially controlling, membrane behavior in experimental settings.