Free-molecular gas flow through the highfrequency oscillating membrane Abstract. The possibility of using a high frequency oscillating track membranes as diffusion membranes for gas separation was studied. High frequency forced oscillation of the membrane was considered because of assumption that the membrane conductivity for a given gas can be controlled by varying the frequency and amplitude of oscillation. The problem about freemolecular gas flow through a oscillating in its plane membrane was stated and the possibility of separation of gases using such a device was investigated. Also, optimal values of membrane oscillation parameters for most efficient gas separation have been found.