Described here are apparatuses and methods for producing a composition comprising nano-bubbles dispersed in a liquid carrier. One such method includes flowing a liquid carrier from an inlet through at least two channels each including a triboelectric material, including flowing the liquid carrier such that a Reynolds number of the flow of the liquid carrier through the at least two channels is less than 3000. Flowing the liquid carrier through the at least two channels produces vibrational energy that causes: (i) the liquid carrier to contact the triboelectric material such that an electric charge is generated in the triboelectric material; and (ii) the liquid carrier to separate from the triboelectric material such that the electric charge is discharged to the liquid carrier to form nano-bubbles dispersed in the liquid carrier.