The curvature-induced polarization (i.e. flexoelectricity) of lipid bilayers produces ac currents (I-vib) on application of vibrations. Binding of aromatic amphiphilic ions to one or both interfaces of a planar bilayer membrane decreases the amplitude of I-vib. On asymmetric binding of such ions I-vib is further reduced to a minimum at an applied de voltage (V-min), which has a sign driving the ion outward and a magnitude determined by the lipophilic group of the amphiphile. A voltage with reversed sign always increases I-vib. The mobile lipophilic ion, tetrakis(p-chlorophenyl)borate, can amplify I-vib by similar to 10-fold by enlarging the polarizibility but causes little shift of V-min. The novel voltage dependence of I-vib induced by amphiphilic ions is attributed to the influence of their relocalization and orientation on the surface tension of the bilayer. This finding offers a new method for study of molecular interactions at the lipid-water interface and an entry into molecular mechanoelectric sensors.