The data showed physical changes of vesicles, i.e. elongation, induced diffusion of the fluorescent dye, and increased attractions between vesicles. These effects were reversible and occured only during irradiation. Since the average temperature change was very small the effects can not be attributed to thermal mechanisms.
The authors assume that the interaction of millimeter waves with lipid bilayer leads to changes at the membrane-water interface, where charged and dipolar residues of molecules are located.