Effect of ultrasound on a bilayer lipid membrane

The effects of continuous wave ultrasound at a frequency of 1 MHz in the intensity range of 0-1.4 W/cm2 on an oxidized cholesterol bilayer lipid membrane (BLM) were observed. Ultrasound at 1.5 W/cm2 broke the membrane; in the range from 0.5 to 1.4 W/cm2, it accelerated the draining of the bulk lipid solution from the annulus to the Teflon support. At all intensities it has no effect on the conductance, the capacitance, or the dependence of each on the voltage applied across the membrane. Electrical parameters were measured in the presence of aqueous solutions of NaCl, KCl, and distilled water. The motivation and results of this project are explained in relation to an overall objective of determining the specific effects of ultrasound on biological membranes.