image: Schematic of an active cell membrane. In a typical active biological process, active proteins (shown in a variety of colors) in a cell membrane (shown in blue) interact with various biological components, such as the ATP molecules (shown in white and red). These interactions of active proteins generate active noise (fluctuation) force within a cell membrane, mechanically affecting the out-of-plane displacement of a cell membrane. Due to the flexoelectric coupling of a cell membrane, changes in out-of-plane displacement induce changes in the transmembrane voltage of a cell membrane,
resulting in energy harvesting, active transport of ions, and the generation of electric current across the cell membrane.
Credit: Pratik Khandagale, Liping Liu, and Pradeep Sharma
Researchers develop a theoretical framework that shows how living cell membranes can generate electricity from molecular fluctuations. Pradeep Sharma and colleagues created a model demonstrating that active biological processes, such as protein dynamics and ATP hydrolysis, create membrane fluctuations that could produce transmembrane voltages via flexoelectricity. Such transmembrane voltages can reach 90 millivolts. Voltage changes can happen on millisecond timescales, matching typical action potential curves for neurons. The authors’ framework predicts that active membrane fluctuations could drive ion transport against electrochemical gradients. The authors relate membrane elastic and dielectric properties to the polarity and direction of ion transport. In the future, the framework could be extended to multicellular assemblies to explore how active fluctuations drive collective bioelectric phenomena at the tissue scale. According to the authors, the mechanism provides a physical basis for understanding sensory processes, neuronal firing, energy harvesting in living cells, and may provide a potential link between the world of brain neuron functioning and the discovery of bio-inspired and physically intelligent materials.
Journal
PNAS Nexus
Article Title
Flexoelectricity and the fluctuations of (active) living cells: Implications for energy harvesting, ion transport, and neuronal activity
Article Publication Date
16-Dec-2025