A breast milk collection device includes a reservoir volume and an adaptor having one end to receive a woman's breast. The adaptor has a drip tube communicating with the reservoir. A source of cyclical application and relief of vacuum force is applied to the woman's breast located in the adaptor for the expression of breast milk. A one-way assembly permits breast milk to enter the reservoir and to submerge the valve element. The valve assembly includes a flexible barrier having an interior hollow chamber in fluid communication with said cyclical source of vacuum force and relief pressure, the flexible barrier fluidly isolating the source from the reservoir. The flexible barrier inflatably expands when relief pressure is applied to the interior of the flexible barrier, the flexible barrier becoming deflated when a vacuum force is applied to the hollow interior of the flexible barrier.
