Interactions between millimeter waves and artificial biological membranes

The objective of our work is to study the potential influence of non-thermal power level 60GHz radiation on the artificial biological membranes. Different types of characterization of lipid single layers are used: 1) measurements of superficial tension by Wilhelmy method and 2) observation by atomic force microscopy (AFM). Two major phospholipid constituents of biological membranes are considered: DPPC, DOPC. The results obtained for different power levels and irradiation times are compared and discussed. In the case of DPPC lipids, measurements of superficial pressure of the phospholipid membrane showed an increase of surface pressure of the monomolecular layer for a low level of superficial power density. The analysis of images obtained by AFM before and after millimeter wave radiation treatment did not show significant modifications in the structure of the membrane in which the lipids were found in co-existence of two phases (liquid-expanded state and liquid-condensed state).